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DIN-100 SERIES USERS MANUAL

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1. 1RR Response Upto this point all communications have been sent at 300 baud The module will notrespondto any further communications at 300 baud because itis now running at 9600 baud Atthis pointthe host computer or terminal must be set to 9600 baud to continue operation If the module does not respond to the new baud rate most likely the setup data is incorrect Try various baud rates from the host until the module responds The last resort is to set the module to Default Mode where the Setup amp SetUp Command 5 6 baud rate is always 300 Bit 4 Bit 4 is used to enable or disable extended addressing mode Table 5 2 Byte 2 Linefeed Parity Addressing and Baud Rate FUNCTION DATA BIT e o a 007 44 LINEFEED 1 NO LINEFEED 0 NO PARITY NO PARITY EVEN PARITY ODD PARITY NORMAL ADDRESSING EXTENDED ADDRESSING 38400 BAUD 19200 BAUD 9600 BAUD 4800 BAUD 2400 BAUD 1200 BAUD 600 BAUD 300 BAUD oooooooo 5 0 0 0 0 Byte 3 This byte contains the setup information for several seldom used options The default value for this byte is 01 Disable CJC RTD 3 4 Wire Trigger Edge Select The setup information stored in bit 4 has different meanings depending on the DIN 100 model number Disable CJC this function pertains only to the DIN 130 series of thermo couple input modules If the bit is set to 1 the Cold Junction Compensation is disabled T
2. The maximum response message length is 20 characters A command response sequence is not complete until a valid response is received The host may not initiate a new command until the response from a previous command is complete Failure to observe this rule will result in communications collisions A valid response can be in one of three forms 1 a normal response indicated by a prompt 2 an error message indicated by a prompt 3 a communications time out error When a module receives a valid command it must interpret the command perform the desired function and the communicate the response back to the host Each command has an associated delay time in which the module is busy calculating the response If the host does not receive a response in an appropriate amount of time specified in Table 4 1 a communications time outerror has occurred After the communications time out itis assumed that no response data is forthcoming This error usually results when an improper command prompt or address is transmitted Long Form Responses When the pound sign command prompt is used the module responds with a long form response This type of response will echo the command message supply the necessary response data and will add a two character checksum to the end of the message Long form responses are used when the host wishes to verify the command received by the module The checksum is included to verify the integ
3. BAD CHECKSUM This error is caused by an incorrect checksum included in the command string The module recognizes any two hex characters appended to a command string as checksum Usually a BAD CHECKSUM error is due to noise or interference on the communications line Often repeating the command solves the problem If the error persists either the checksum is calculated incorrectly or there is a problem with the communications channel More reliable transmissions might be obtained by using a lower baud rate Command Set 4 13 COMMAND ERROR This error occurs when the two character command is not recognized by the module Often this error results when the command is sent with lower case letters All valid commands are upper case NOT READY If a module is reset it performs a self calibration routine which takes 2 3 seconds to complete Any commands sent to the module during the self calibration period will result ina NOT READY error When this occurs simply wait a couple seconds and repeat the command The module may be reset in three ways a power up reset a Remote Reset RR command or an internal reset All modules contain a watchdog timer to ensure proper operation of the microprocessor The timer may be tripped if the microprocessor is executing its program improperly due to power transients or static discharge If the NOT READY error persists for more than 30 seconds check the power supply to be sure it is within sp
4. Black R G Green ikp We Yellow Up to 4 000 Feet po HOST 2200 2200 H5 485 po Local POWER SUPPLY Communications 3 5 EARTH 500 iR DATA iG 500 DATA Gi 500 DATA iG Figure 3 1 5 485 Network Chapter 4 ASCII Command Set The DIN 100 modules operate with a simple command response protocol to control all module functions A command must be transmitted to the module by the host computer or terminal before the module will respond with useful data A module can never initiate a communications sequence A variety of commands exists to exploit the full functionality of the modules A list of available commands and a sample format for each command is listed in Table 4 1 Command Structure Each command message from the host must begin with command prompt character to signal to the modules that a command message is to follow There are two valid prompt characters a dollar sign character is used to generate a short response message from the module A short response is the minimum amount of data necessary to complete the command The second prompt character is the pound sign character which generates long responses will be covered later in this chapter The prompt character must be followed by a single address character identifying the module to which the command is directed Each module attached to a common communications port must be setup with
5. 96 60 01100000 224 0 11100000 97 61 01100001 225 E1 11100001 b 98 62 01100010 226 2 11100010 99 63 01100011 227 11100011 100 64 01100100 228 4 11100100 101 65 01100101 229 11100101 f 102 66 01100110 230 6 11100110 0 103 67 01100111 231 E7 11100111 h 104 68 01101000 232 8 11101000 105 69 01101001 233 9 11101001 106 6A 01101010 234 EA 11101010 k 107 01101011 235 11101011 108 6C 01101100 236 11101100 m 109 60 01101101 237 ED 11101101 n 110 6 01101110 238 11101110 o 111 6F 01101111 239 11101111 112 70 01110000 240 FO 11110000 113 71 01110001 241 F1 11110001 r 114 72 01110010 242 F2 11110010 115 73 01110011 243 11110011 t 116 74 01110100 244 11110100 ASCII Tables A 4 A D Hex Binary D Hex Binary 117 75 01110101 245 F5 11110101 v 118 76 01110110 246 F6 11110110 w 119 77 01110111 247 11110111 x 120 78 01111000 248 F8 11111000 y 121 79 01111001 249 F9 11111001 z 122 01111010 250 FA 11111010 123 7B 01111011 251 FB 11111011 124 7C 01111100 252 11111100 125 7D 01111101 253 FD 11111101 126 7E 01111110 254 FE 11111110 127 7 01111111 255 FF 11111111 Appendix B DIN 160 Data Sheet The Frequency Input modules feature a versatile input stage that can be used in a variety of applications Figure B 1 is a block diagram of the input signal conditioning Input protection Isolation Output to up Comparator H
6. all the signal conditioning circuitry has been lumped into one block the analog digital converter A D Autozero and autocalibration is performed internally and is transparent to the user The full scale output of the A D converter may be trimmed using the Trim Span TS command The TS command adjusts calibration values stored internally inthe EEPROM The TS command should only be used to trim the accuracy of the unit with a laboratory standard reference applied to the sensor input The trimmed data flows into either of two digital filters The filter selection is performed automatically by the microprocessor after every A D conversion The filter selection depends on the difference of the current A D output data and the previous data stored in the output data register If the least significant decimal digit from the A D differs from the old output data by more than 10 counts the large signal filter is selected Ifthe change is less than 10 counts the small signal filter is used The two filter system allows for different degrees of filtering depending on the rate of the input change For steady state signals the small signal filter averages out noise and small input changes to give a stable steady state output The large signal filter is activated by step changes or very noisy input signals The time constants for the two filters can be specified independently with the SetUp SU command The filter values are stored in nonvolatile memory
7. 141 model for RTD s has 0 1 degree output resolution The appropriate number of digits for this module is 6 to mask off the 0 01 digit which has no meaningful data In some cases the user may want to limit the output resolution to 1 degree To do this select bits 6 and 7 to display 5 digits With this selection the right most two digits will always be set to 0 The number of displayed digits affects only data received from an RD or ND command Large Signal Filter Bits 3 4 5 Small Signal Filter Bits 0 1 2 The modules contain a versatile single pole low pass digital filter to smooth out unwanted noise caused by interference or small signal variations The digital filter offers many advantages over traditional analog filters The filering action is done completely in firmware and is not affected by component drifts offsets and circuit noise typically found in analog filters The filter time constant is programmable through the SetUp SU command and can be changed at any time even if the module is remote from the host The digital filter features separate time constants for large and small signal variations The Large Signal Filter time constant is controlled by bits 3 4 5 This time constant is used when large signal variations are present on the input The Small Signal Filter time constant is controlled by bits 0 1 2 This filter time constantis automatically selected when input signal variations are small The microprocessor in
8. 7 55 37 00110111 183 B7 10110111 8 56 38 00111000 184 8 10111000 9 57 39 00111001 185 B9 10111001 58 SA 00111010 186 BA 10111010 59 3B 00111011 187 10111011 lt 60 3C 00111100 188 BC 10111100 61 3D 00111101 189 10111101 gt 62 00111110 190 BE 10111110 63 00111111 191 10111111 64 40 01000000 192 11000000 65 41 01000001 193 C1 11000001 6 42 01000010 194 2 11000010 67 43 01000011 195 C3 11000011 D 68 44 01000100 196 C4 11000100 E 69 45 01000101 197 C5 11000101 F 70 46 01000110 198 C6 11000110 G 71 47 01000111 199 C7 11000111 72 48 01001000 200 8 11001000 73 49 01001001 201 C9 11001001 J 74 4A 01001010 202 11001010 K 75 4B 01001011 203 11001011 ASCII Tables A 3 A D Hex Binary D Hex Binary L 76 4C 01001100 204 11001100 M 77 4D 01001101 205 CD 11001101 78 4 01001110 206 11001110 79 01001111 207 11001111 80 50 01010000 208 00 11010000 Q 81 51 01010001 209 01 11010001 82 52 01010010 210 02 11010010 5 83 53 01010011 211 03 11010011 T 84 54 01010100 212 04 11010100 0 85 55 01010101 213 05 11010101 86 56 01010110 214 06 11010110 W 87 57 01010111 215 07 11010111 X 88 58 01011000 216 08 11011000 Y 89 59 01011001 217 09 11011001 Z 90 5A 01011010 218 DA 11011010 91 5B 01011011 219 11011011 92 5C 01011100 220 DOC 11011100 93 5D 01011101 221 DD 11011101 94 5E 01011110 222 11011110 _ 95 01011111 223 11011111
9. errors In situations where many modules are used on a long line voltage drops in the power leads becomes an important consideration The GND wire is used both as a power connection and the common reference for the transmission line receivers in the modules Voltage drops in the GND leads appear as a common mode voltage to the receivers The receivers are rated for a maximum of 7V of common mode voltage For reliable operation the common mode voltage should be kept below 5V To avoid problems with voltage drops modules may be powered locally rather than transmitting the power from the host Inexpensive calculator type power supplies are useful in remote locations When local supplies are used be sure to provide a ground reference with a third wire to the host or through a good earth ground With local supplies and an earth ground only two wires for the data connections are necessary Communications Delay All DIN 100 modules are setup at the factory to provide two units of communications delay after acommand has been received see Chapter 5 This delay is necessary when using host computers that transmit a carriage return as a carriage return linefeed string Without the delay the linefeed character may collide with the first transmitted character from the module resulting in garbled data If the host computer transmits a carriage return as asingle character the delay may be setto zero to improve communications response time
10. protected command must be preceded individu ally with a WE command For example Command 1WE Response Command 1WE Response 1WEF7 Command Set 4 12 If a module is write enabled and the execution of a command results in an error message other than WRITE PROTECTED the module will remain write enabled until a command is successfully completed resulting in an prompt This allows the user to correct the command error without having to execute another WE command Write Extended Address WEA ERROR MESSAGES The DIN 100 modules feature extensive error checking on input commands to avoid erroneous operation Any errors detected will result in an error message and the command will be aborted All error messages begin with followed by the channel address a space and error description The error messages have the same format for either the or prompts For example 1 SYNTAX ERROR There are eight error messages and each error message begins with a different character It is easy for a computer program to identify the error without having to read the entire string ADDRESS ERROR There are six ASCII values that are illegal for use as a module address NULL 00 0D 24 4 23 7B and 70 The ADDRESS ERROR will occur when an attempt is made to load an illegal address into a module with the SetUp SU command An attempt to load an address greater than 7F will produce an error
11. syntax for the Extended Addressing mode is that it uses a two charac ter address A typical command in Extended Address mode would look like this Command 01 Response is Both the command and response are terminated with carriage returns Note that the command uses a two character address 01 There are two benefits to using Extended Addressing with the DIN 100 1 Greatly expanded addressing capability 2 Allow for a more structured addressing method in large systems With single byte addressing of the normal command structure address space is limited to 122 points Extended addressing allows an address ing range of 249 points Structured Addressing Even for a relatively small system it can be advantageous to employ a hierarchical addressing system as used in Fig 7 1 This is particularly true in systems that consist of many sites that are identical From a host software standpoint each site can be treated identically with the same module addresses with each site having a different DIN 100 address Extended Address Syntax The command syntax used with Extended Addressing is quite similar to the normal protocol The Extended Address commands are initiated with a character left curly brace ASCII 7B or a character right curly brace ASCII 7E The prompt is analogous to the prompt in that it returns the shortest possible response to complete the command The prompt is similar to the promp
12. 0 zero output Response The TZ command will load a data value into the Output Offset Register to force the output to read zero The module will compensate for any previous value loaded into the Output Offset Register If another output reading is taken it will show that the offset has been eliminated Command 1RD Response 00000 00 Although the TZ command is most commonly used to null an output to zero it may be used to offset the output to any specified value Assume that with the previously nulled load cell system we performed this command Command 172 00100 00 Response The new data output with no load applied would be Command 1RD Response 00100 00 The load cell output is now offset by 100 The offset value stored by the TZ commandis stored in nonvolatile memory and may be read back with the Read Zero RZ command and cleared with the Clear Zero CZ command The SetPoint SP command will write over any value loaded by the TZ command Write Enable WE Each module is write protected against accidental changing of alarms limits setup or span and zero trims To change any of these write protected parameters the WE command must precede the write protected command The response to the WE command is an asterisk indicating that the module is ready to accept a write protected command After the write protected command is successfully completed the module becomes automatically write disabled Each write
13. 01101 N 14 OE 00001110 142 8E 10001110 O 15 OF 00001111 143 8 10001111 P 16 10 00010000 144 90 10010000 Q 17 11 00010001 145 91 10010001 R 18 12 00010010 146 92 10010010 S 19 13 00010011 147 93 10010011 T 20 14 00010100 148 94 10010100 U 21 15 00010101 149 95 10010101 V 22 16 00010110 150 296 10010110 W 23 17 00010111 151 97 10010111 24 18 00011000 152 98 10011000 Y 25 19 00011001 153 99 10011001 Z 26 1 00011010 154 9 10011010 27 1B 00011011 155 9 10011011 28 1C 00011100 156 9 10011100 29 1D 00011101 157 90 10011101 30 1E 00011110 158 9E 10011110 31 1 00011111 159 9 10011111 32 20 00100000 160 10100000 33 21 00100001 161 1 10100001 4 34 22 00100010 162 2 10100010 ASCII Tables A 2 A D Hex Binary D Hex Binary 35 23 00100011 163 10100011 36 24 00100100 164 4 10100100 37 25 00100101 165 5 10100101 amp 38 26 00100110 166 10100110 39 27 00100111 167 10100111 40 28 00101000 168 8 10101000 41 29 00101001 169 9 10101001 42 2A 00101010 170 AA 10101010 43 2B 00101011 171 AB 10101011 44 2C 00101100 172 AC 10101100 45 2D 00101101 173 AD 10101101 46 2E 00101110 174 10101110 47 2F 00101111 175 10101111 0 48 30 00110000 176 0 10110000 1 49 31 00110001 177 B1 10110001 2 50 32 00110010 178 B2 10110010 3 51 33 00110011 179 10110011 4 52 34 00110100 180 B4 10110100 5 53 35 00110101 181 B5 10110101 6 54 36 00110110 182 6 10110110
14. 310701C2 110 113 114 31070142 13X 31070142 141 142 143 112 31070182 145 15X 310701C2 16X 310701 0 17 31070100 Chapter 6 Digital I O Functions The DIN 100 series features the DIN 171 module with six digital inputs and the DIN 172 module with six digital outputs Digital Outputs A digital output consists of an open collector transistor controlled by the host using the Digital Output DO command See Figure 6 1 The open collector configuration is used to provide maximum versatility in interfacing to solid state relays SSR s or to standard logic levels such as TTL or CMOS Each digital output can sink up to 100mA and can withstand up to 30V Power in the transistor must be limited to 300mW The emitter of each transistor is tied to the GND terminal on the input connector A typical connection of a digital output is shown in Figure 6 1 In this case a solid state relay is controlled by the DIN 172 module The SSR can then be used to control AC power to alarms heaters pumps etc A typical connec tion to a logic input is shown in Figure 6 2 In some cases the common mode voltage of the GND terminal may be significantly different from the ground potential of the logic input to be interfaced This may occur when H1 amp HB2 Limit Current to Max Figure 6 1 Digital Outputs Used With Relays the module is powered remotely In this case an opto isolator may be used to eliminate the common mode voltage Se
15. 50 Data Sheet DIN 100 Specifications Modbus Protocol WARRANTY DGH warrants each DIN 100 series module to be free from defects in materials and workmanship under normal conditions of use and service and will replace any component found to be defective on its return to DGH transportation charges prepaid within one year of its original purchase DGH assumes no liability expressed or implied beyond its obligation to replace any component involved Such warranty is in lieu of all other warranties expressed or implied WARNING The circuits and software contained in DIN 100 series modules are proprietary Purchase of these products does not transfer any rights or grant any license to the circuits or software used in these products Disassembling or decompiling of the software program is explicitly prohibited Reproduction of the software program by any means is illegal As explained in the setup section all setups are performed entirely from the outside of the DIN 100 module There is no need to open the module because there are no user serviceable parts inside Removing the cover or tampering with modifying or repairing by unauthorized personnel will automatically void the warranty is not responsible for any consequential damages RETURNS When returning products for any reason contact the factory and request a Return Authorization Number and shipping instructions Write the Return Authorization Number on the outside of the shi
16. A Response 01 05 0000 FF 00 8C In the command string 01 isthe slave address 05 isthe Force Single Coil command 00 00 is the address of the digital output bit 00 07 would equal BO7 FF 00 indicates that the desired bit will be set or turned on 8C 3A is the CRC for this message The valid address range of digital output bits is 00 00 to 00 07 Any other address will produce an exception error response To clear or turn off digital output bit replace the FF 00 string with 00 00 For example Command 01 05 0003 0000 3D Response 01 05 0003 0000 Command values other than FF 00 or 00 00 will result in an exception error response Function 06 Preset Single Register Return to DIN 100 ASCII Proto col The Preset Single Register function 06 can be used to temporarily suspend the Modbus RTU protocol and force the module into DIN 100 ASCII protocol Write a value of 0000 to Modbus register 40001 to temporarily suspend Modbus RTU mode The module will then communicate using the DIN 100 ASCII protocol only The DIN 100 ASCII protocol can be used to alter or check setup information and or for troubleshooting purposes The module will continue to communi cate using the ASCII protocol until either a Remote Reset RR command RR is received or the power is cycled At which time the module will return to the Modbus RTU protocol mode Refer to the DIN 100 ASCII Modbus Disable command MBD for more in
17. BM BASIC a carriage return CR is always followed by linefeed LF The DIN 100 modules will respond immediately after a command terminated by a CR and will ignore the linefeed To avoid acommunications collision between the linefeed and the module response the module should be setup to delay by 2 units Table 5 3 Byte 3 Options FUNCTION DATA BIT CJC DIN 130 S NO CJC DIN 130 S 3 WIRE DIN 140 S 4 WIRE DIN 140 S NO DELAYS 2 BYTE TIME DELAYS 4 BYTE TIME DELAYS 6 BYTE TIME DELAYS Setup amp SetUp Command 5 8 Byte 4 This setup byte specifies the number of displayed digits and the digital filter time constants Number of displayed digits For ease of use the data outputs of all modules are standardized to a common 7 digit output consisting of sign 5 digits decimal point and two more digits Typical output data looks like 00100 00 However best case resolution of the A D converter is 1 part in 32 768 In some cases the resolution of the output format is much greater than the resolution of the measurement system In such cases the trailing digits of the response would display meaningless information Bits 6 and 7 are used to insert trailing zeros into the output data to limit the output resolution and mask off meaningless digits Bit 7 Bit 6 0 0 XXXX0 00 4 displayed digits 0 1 XXXXX 00 5 displayed digits 1 0 XXXXX X0 6 displayed digits 1 1 XXXXX XX 7 displayed digits For example the DIN
18. CRC for this message In the response string 01 isthe slave address 04 isthe command 02 indicated the number of data bytes in the message in this case two bytes 1457 isthe analog data F7 CE is the CRC for this message This sample command reads two registers Command 01 04 0000 0002 71 CB Response 01 04 04 1458 0000 7F A7 The analog data from Modbus register 30001 is 14 58 The data from Modbus register 30002 is set to 00 00 The analog data is scaled so that 00 01 represents the Negative Full Scale value programmed into the module FF FE represents the Positive Full Scale value programmed into the module For example for a 10 volt input module 00 01 corresponds to 10 volts 80 00 corresponds to 0 volts FF FE corresponds to 10 volts A negative overload where the analog input exceeds minus full scale value is represented by 00 00 hexadecimal A positive overload where the analog input exceeds the positive full scale value is represented by FF FF hexadecimal Function 05 Force Single Coil Digital Output The Force Single Coil function 05 is used to set or clear a single Modbus output relay coil Each output relay coil is considered a digital output on the DIN 100 series modules Modbus Coil 1 equals DIN 100 series digital output bit BOO and Coil 6 equals digital output bit 05 The following example can be used to turn on digital output bit BOO Modbus Protocol F 8 Command 01 05 0000 FF 00 8C 3
19. D 24 23 7B 7D which are ASCII codes for the characters NUL CR and Using these codes for an address will cause an ADDRESS ERROR and the setup data will remain unchanged This leaves atotal of 122 possible addresses that can be loaded with the SU command It is highly recommended that only ASCII codes for printable characters be used 21 to 7E which greatly simplifies system debugging with a dumb terminal Refer to Appendix A for a list of ASCII codes Table 5 1 lists the printable ASCII codes that may be used as addresses Table 5 1 Byte 1 ASCII Printable Characters i k 4 r t u v w x y z UOZZEI TACTC IOTmOOUPQ oVvVHA o o 40013 0N 207 Setup amp SetUp Command 5 4 Byte 2 Byte 2 is used to configure some of the characteristics of the communica tions channel linefeeds parity and baud rate Linefeeds The most significant bit of byte 2 bit 7 controls linefeed generation by the module This option can be useful when using the module with a dumb terminal All responses from the DIN 100 are terminated with a carriage return ASCII 0D Most terminals will generate a automatic linefeed when a carriage return is detected However for terminals that do not have this capability the 01000 module can generate the linefeed if desired By setting bit 7 to 1 the module will send a linefeed ASCII 0A before and after each response If bit 7 is cleared 0 no lin
20. DIN 100 SERIES USERS MANUAL REVISED 06 2000 DGH CORPORATION P O BOX 5638 MANCHESTER NH 03108 TELEPHONE 603 622 0452 FAX 603 622 0487 URL http www dghcorp com The information in this publication has been carefully checked and is believed to be accurate however no responsibility is assumed for possible inaccuracies or omissions Applications information in this manual is in tended as suggestions for possible use of the products and not as explicit performance in a specific application Specifications may be subject to change without notice DIN 100 modules are not intrinsically safe devices and should not be used in an explosive environment unless enclosed in approved explosion proof housings Warranty CHAPTER 1 CHAPTER 2 CHAPTER 3 CHAPTER 4 CHAPTER 5 CHAPTER 6 CHAPTER 7 CHAPTER 8 CHAPTER 9 CHAPTER 10 Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F TABLE OF CONTENTS 4 Getting Started Default Mode 1 1 Quick Hook Up 1 2 Functional Description Block Diagram 2 2 Communications Data Format 3 2 485 3 2 RS 485 Multidrop System 3 3 Command Set Table of Commands User Commands 4 6 Error Messages 4 12 4 6 Setup Information and Command Command Syntax 5 1 Setup Hints 5 10 Digital I O Function Digital Outputs 6 1 Digital Inputs 6 2 Power Supply Troubleshooting Calibration Extended Addressing ASCII TABLE DIN 160 Data Sheet DIN 140 Data Sheet DIN 1
21. E 3 DIN 140RTDinputs e RTD types 00385 00392 1000 at 0 C 00388 100Q at 25 C Ranges 00385 200 C to 850 C 00392 200 C to 600 C 00388 100 C to 125 C Resolution 0 1 Accuracy 0 3 Span tempco 50 ppm C max Common mode rejection 100dB at 50 60Hz Input connections 2 3 or 4 wire Excitation current 0 25mA Lead resistance effect 3 wire 2 5 of imbalance 4 wire negligible Max lead resistance 500 Input burnout protection to 120Vac Automatic linearization and lead compensation DIN 145 Thermistor Inputs Thermistor types 22520 at 25 C TD Series Ranges 22520 0 C to 100 40 to 150 C Resolution 22520 0 01 TD 0 1 C or F e Accuracy 22520 0 1 0 2 Common mode rejection 100dB at 50 60Hz Input protection to 30Vdc DIN 150 Bridge Inputs Voltage Ranges 30mV 100mV e Resolution 10uV mV spans 0 0296 of FS V span Accuracy 0 05 of FS max Common mode rejection 100dB at 50 60Hz Input burnout protection to 30Vdc Offset Control Full input range Excitation Voltage 5V 10Vdc 60mA max e Zero drift 1uV C max Span tempco 50ppm C max DIN 160 Timer and Frequency Inputs Inputimpedance 1M Switchinglevel selectableOV 2 5 Hysteresis Adjustable 10mV 1 0V Inputburnoutprotection 250 Vac Specifications E 4 Frequency Inp
22. GNAL FILTERING 0 25 SECOND TIME CONSTANT 0 5 SECOND TIME CONSTANT 1 0 SECOND TIME CONSTANT 2 0 SECOND TIME CONSTANT 4 0 SECOND TIME CONSTANT 8 0 SECOND TIME CONSTANT 16 0 SECOND TIME CONSTANT 3 coeo3300 o oO O0O 0O0 Setup Hints Until you become completely familiar with the SetUp command the best method of changing setups is to change one parameter at atime and to verify that the change has been made correctly Attempting to modify all the setups at once can often lead to confusion If you reach a state of total confusion the best recourse is to reload the factory setup shown in Table 5 5 and try again changing one parameter at a time Use the Read Setup RS command to examine the setup information currently in the module as a basis for creating a new setup Setup amp SetUp Command 5 11 By using the RS command and changing one setup parameter at atime any problems associated with incorrect setups may be identified immediately Once a satisfactory setup has been developed record the setup value and use it to configure similar modules If you commit an error in using the SetUp command it is possible to lose communications with the module In this case it may be necessary to use the Default Mode to re establish communications Table 5 5 Factory Setups by Model All modules from the factory are set for address 1 300 baud no parity DIN 100 Series Model Number Setup Message 111 115 125
23. ITE PROTECTED error will result Chapter 5 Setup Information SetUp Command The DIN 100 modules feature a wide choice of user configurable options which gives them the flexibility to operate on virtually any computer or terminal based system The user options include a choice of baud rate parity address and many other parameters The particular choice of options for a module is referred to as the setup information The setup information is loaded into the module using the SetUp SU command The SU command stores 4 bytes 32 bits of setup information into a nonvolatile memory contained in the module Once the information is stored the module can be powered down indefinitely 10 years minimum without losing the setup data The nonvolatile memory is implemented with EEPROM so there are no batteries to replace The EEPROM has many advantages over DIP switches or jumpers normally used for option selection The module never has to be opened because all ofthe options are selected through the communications port This allows the setup to be changed at any time even though the module may be located thousands of feet away from the host computer or terminal The setup information stored in a module may be read back at any time using the Read Setup command RS The following options can be specified by the SetUp command Channel address 122 values Linefeeds Parity odd even none Baud rate 300 to 38 400 Addressing Mode Extended Norma
24. Typically the small signal filter is setto a larger time constant than the large signal filter This gives very good noise rejection along with fast response to step inputs The scaled data is summed with data stored in the Output Offset Register to obtainthe final output value The output offset is controlled by the user and has many purposes The data in the Output Offset Register may be used to trim any offsets caused by the input sensor It may be used to null out undesired signal such as atare weight The Trim Zero TZ commandis used to adjust the output to any desired value by loading the appropriate value in the offset register The offset register data is nonvolatile The value stored in the offset register may be read back using the Read Zero RZ command Data loaded in with the SP command will be read back with the sign changed The output register may be reset to zero with the Clear Zero CZ command Functional Description 2 2 The output data may be read with the Read Data RD command In some cases when a computer is used as a host the same data value may be read back several times before it is updated with a new A D conversion The DIN 170 general purpose digital outputs are open collector transistor switches that may be controlled by the host with the Digital Output DO command They are designed to activate external solid state relays to control AC or DC power circuits The output may also be used to interface to other log
25. and string make up the Cyclical Redundancy Check CRC used to check for errors in the message There are no prompt or terminating characters in the messages messages must be transmitted as continuous strings Messages are termi nated by a silent interval of at least 3 5 character times A silent interval of more than 1 5 character times marks the beginning of the next message Therefore it is mandatory that the RS 485 bus must be biased in the MARK condition during the silent interval This is usually accomplished by pull up and pull down resistors on the communications line A typical response to this example command could be 01 04 02 8000 08 The 01 and 04 characters echo the slave address and the command function For this particular command function the 02 character indicates the number of data characters to follow in this case 2 characters The two character string 80 00 is the value read from Modicon input register 30001 Register data is read back as 16 bits The remaining two characters D8 FO is the CRC for the response The A1000 and DIN 190 series of RS 232 to RS 485 protocol converters and repeaters will not operate with the 9 bit data characters used by the Modbus protocol Getting Started Modbus Protocol F 3 The DIN 100 series modules are initialized at the factory to communicate using the DIN 100 ASCII protocol This allows for all setup and configura tions to
26. annel analog input Maximum input to output at 60Hz 500V rms e Leakage current input to output at 115Vrms 60Hz lt 2uA rms 15 bit measurement resolution 8 conversions per second Autozero amp autocalibration no adjustment pots Digital 8 bit CMOS microcomputer Digital scaling linearization and calibration Nonvolatile memory eliminates pots and switches Digital filtering Small and large signal with user selectable time constants from 0 to 16 seconds Communications Communications in ASCII via RS 232C RS 485 ports Selectable baud rates 300 600 1200 2400 4800 9600 19200 38400 NRZ asynchronous data format 1 start bit 7 data bits 1 parity bit and 1 stop bit Parity odd even none User selectable channel address ASCII format command response protocol Up to 122 multidrop modules per host serial port Communications distance up to 4 000 feet RS 485 Transient suppression on RS 485 communications lines Communications error checking via checksum Can be used with dumb terminal Scan up to 250 channels per second All communications setups stored in EEPROM Power Requirements 5 0 5 0 75W max DIN 150 2 0W max Internal switching regulator Protected against power supply reversals Specifications E 2 Environmental Temperature Range Operating 25 C to 70 Storage 25 C to 85 Relative Humidity 0 to 95 non
27. at shuts down all circuits in the module at approximately 4 5 Vdc All power supply specifications are referred to the module connector the effects of line voltage drops must be considered when the module is powered remotely For modules with sensor excitation consult individual data sheets for power requirements The low voltage detection circuit shuts down the module at approximately 4 5Vdc If the module is interrogated while in a low power supply condition the module will not respond Random NOT READY error messages could indicate that the power supply voltage is periodically drooping below the 4 7V minimum In some cases a small number of modules may be operated by stealing power from a host computer or terminal Small systems may be powered by using wall mounted calculator type modular power supplies These units are inexpensive and may be obtained from many retail electronics outlets For best reliability modules operated on long communications lines 2500 feet should be powered locally using small calculator type power units This eliminates the voltage drops on the Ground lead which may interfere with communications signals In this case the V terminal is connected only to the local power supply The Ground terminal must be connected back to the host to provide a ground return for the communications loop All DIN 100 modules are protected against power supply reversals Chapter 8 Troubleshooting Symptom Module is n
28. be easily performed using the DIN 100 setup software or a dumb terminal After the setup process has been completed the DIN 100 can be placed in Modbus RTU protocol mode using the MBR command Disable the Modbus mode using the Modbus Disable command Quick start steps 1 Connect a power supply to the DIN 100 between Vs terminal GND terminal The regulated supply voltage must be 5 0Vdc 2 Properly connect the DIN 100 series to a computer using the quick hook up diagrams in chapter 1 of this manual using either RS 232 or RS 485 serial port 3 Locate the Windows Utility software CD ROM and run the setup exe file to install the software A DGH Data Acquisition menu selection will be added to the Windows Start Programs menu The Utility Software will be listed under that selection 4 Configure the host computer serial ports by selecting main menu selection Edit and Serial Ports Selectthe correct COMx port baud rate and Parity type Note If the Default pin DIN 100 is connected to GND then select 300 baud as host computer baud rate and select no parity 5 Select main menu Setup and enter the DIN 100 device address and model number For example select 111 DIN 100mV RS 485 Out 6 Atthe next configuration screen make the necessary alterations to Baud Rate Parity type and other required parameters Drop down the Commu nications Protocol list box and select Modb
29. be zero as DIN 100 series modules contain up to eight digital outputs 9F 06 is the CRC for this message The valid address range of digital output bits is 00 00 to 00 07 Any other address will produce an exception error response To clear or turn off the digital output bits replace the 00 03 string with 00 00 For example Command 01 0000 0002 00 00 DF07 Response 01 OF 0000 0002 D4 0A Modbus RTU Enable MBR Modbus Protocol F 10 To place any DIN 100 module in Modbus protocol mode use the Modbus RTU MBR command The MBR command must be used to specify the Modbus device address and enable the Modbus protocol mode The device address consists of a two character hexadecimal value and is stored in EEPROM The two byte address specified is translated to a one byte 8 bit address required by the Modbus protocol The example below can be used to specify a Modbus device address of 01 Command 1MBRO1 Response B Command 1MBR01 Response 1MBR019D After the Modbus address is specified a reset is necessary to activate the Modbus protocol mode The reset may be accomplished in one of three ways 1 Removing power for about 10 seconds to perform a power up reset 2 Momentarily grounding the Default pin 3 Issue a Write Enable WE command followed by a Remote Reset RR command After a reset is performed the module is in Modbus protocol mode Modbus Disable MBD The Modbus Disable MBD command is used to d
30. bridge Command 1RD Response 00043 21 Inthiscase thebridgeexhibitsalargeinitialoffsetof 43 21mV Subtractthis valuefromthe 60mVusefulrange ofthe DIN 152to obtain and input overhead value of 16 79mV to 103 21mV Inthiscasethe 16 79mV overheadis notlarge enoughtocoverthe 30mV thatmay beobtainedfrom thebridge Thebridgemustbetrimmedexternallytobringthe offsettowithin 30mV Itis notnecessary to obtain an exactzerowiththe externaltrim Afterthe external trim has been performed checkthe offset Command 1RD Response 00022 22 DIN 150DataSheet 0 5 Thisvalueiswithinthe 30mV offsetnecessaryto provide enough head roomforthe straingage bridge Trimoutthe remaining offsetwiththe Trim Zero TZ command Command 1WE Response x Command 1TZ 00000 00 Response Thebridgeisnowtrimmedtozero Verify Command 1RD Response 00000 00 The Trim Zero TZ commandmay be usedatanytimetobalanceoutoffsets duetotemperature residualstress tare etc Excitation DIN 150 modules may be ordered with either 5V or 10V excitation Maxi mumexcitationcurrentavailableis40mA Modules with 1 OV excitationmay be usedwith bridges that have inputimpedances of 166 ohms or greater Half bridgesof120 Ostraingagesmaybeusedwith 10V excitationifthe bridgeiscompletedwith 350 resistors Moduleswith 5V excitation will sourcebridgesof85 Theactualexcitation voltage may vary 0 5V fromthe nominal values of 10Vand 5V Howeve
31. ck Hook up to a RS 232 port An RS 485 module may be easily interfaced to an RS 232C terminal for evaluation purposes This connectionis only suitable for benchtop operation and should never be used for a permanent installation Figure 1 2 shows the hook up This connection will work provided the RS 232C transmit output is current limited to less than 50mA and the RS 232C receive threshold is greater than OV All terminals that use 1488 and 1489 style interface IC s will satisfy this requirement With this connection characters generated by the terminal will be echoed back To avoid double characters the local echo on the terminal should be turned off If the current limiting capability of the RS 232C output is uncertain insert 1000 to 1 resistor in series with the RS 232 output In some rare cases it may be necessary to connect the module s DATA pin to ground through a 1000 to 1kQ resistor DIC Power Supply ct GHO TB5VDE iR DRTRX iG DATA DEFAULT INPUT TIMPUT Ca aaa Cat Note f using a DB 25 connector ground is tied to pin 7 Figure 1 2 RS 485 Quick Hook Up with RS 232C Port Chapter 2 Functional Description A functional diagram of a typical module is shown in Figure 2 1 It is a useful reference that shows the data path in the module and to explain the function of many of the module s commands The first step is to acquire the sensor signal and convert it to digital data In Figure 2 1
32. condensing Warranty 12 months on workmanship and material DIN 110 Voltage Inputs e Voltage ranges 10mV 100mV 1V 5 10 100 Resolution 0 0196 of FS 4 digits Accuracy 0 02 of FS max Common mode rejection 100dB at 50 60Hz Zero drift 1 count max autozero e Span tempco 50ppm C max Input burnout protection to 250Vac Input impedance x 1V input 100MQ min gt 5V input 1MO min DIN 120 Current Inputs Current ranges 4 20mAdc Resolution 0 04 of FS Accuracy 0 04 of FS 4 20 Common mode rejection 100dB at 50 60Hz Zero drift 1 count max autozero Span tempco 50ppm C max Voltage drop 0 1 max DIN 130 Thermocouple Inputs Thermocouple types J K T E R S B C factory set e Ranges J 200 C to 760 C 0 to 1820 150 C to 1250 S 0 to 1750 C T 200 to 400 R 0 to 1750 100 C to 1000 C O C to 2315 C Resolution 1 Overall Accuracy error from all sources from 0 to 40 ambient 1 0 J T E 12 5 max S B 300 TO FS Common mode rejection 100dB at 50 60Hz Input impedance 100MQ min e Lead resistance effect lt 20uV per 3500 Open thermocouple indication Input burnout protection to 250Vac Overrange indication Automatic cold junction compensation and linearization Specifications
33. d Coil Status command 02 is the number of data bytes returned 09 is the Digital Output status FF is the Digital Inputs status FF EC is the CRC for this message Function 04 Read Input Register Analog Inputs Read Input Register function 04 is the primary command to acquire analog input data This command function supports reading of up to 16 input registers starting from Modbus slave register 30001 The registers are addressed starting from zero meaning registers 1 16 are addressed as 0 T5 The response data for each channel is returned as two bytes that represent a 16 bit binary value The 16 bit value is scaled as a percentage of the full scale input range The first byte contains the high order bits and the second contains the low order bits The binary analog values for each channel can range from 0000 FFFF hexadecimal Only the register values for channel one are valid as each module contains a single analog input The remaining data values for channels 2 16 will always return as 0000 hexadecimal A typical command and response to read the analog input value from Modbus device address 01 is Command 01 04 0000 0001 31 CA Response 01 04 02 1457 F7 CE In the command string 01 is the slave address 04 is the Read Input Registers command 00 00 is the starting register to be read Modbus address 30001 00 01 specifies the number of registers to be read in this case one register Modbus Protocol F 7 31 CA is the
34. e The Default Mode setup is 300 baud one start bit eight data bits one stop bit no parity any address is recognized Grounding the DEFAULT pin does not change any of the setups stored in EEPROM The setup may be read back with the Read Setup RS command to determine all of the setups stored in the module In Default Mode all commands are available A module in Default Mode will respond to any address except the six identified illegal values NULL CR A dummy address must be included in every command for proper responses The ASCII value of the module address may be read back with the RS command An easy way to determine the address character is to deliberately generate an error message The error message outputs the module s address directly after the prompt Setup information in a module may be changed at will with the SetUp SU command Baud rate and parity setups may be changed without affecting the Default values of 300 baud and no parity When the DEFAULT pin is released the module automatically performs a program reset and config ures itself to the baud rate and parity stored in the setup information The Default Mode is intended to be used with a single module connected to a terminal or computer for the purpose of identifying and modifying setup Getting Started 1 2 values In most cases a module in Default Mode may not be used a string with other modules RS 485 Quick Hook Up Software is not
35. e Figure 6 2 In all cases the current switched by the transistor may not be more than 100mA Digital Functions 6 2 If the module loses power the digital outputs are turned off The outputs will remain off until switched by a Digital Output DO command The digital outputs are not affected by the Remote Reset RR command Digital Inputs Digital inputs are used to sense switch closures and the state of digital signals The inputs are protected to voltages up to 30V and are normally pulled up to the logic 1 condition see Figure 6 2 Digital inputs can be read by the Digital Input DI command Voltage inputs less than 1V are read back as 0 Signals greater than 3 5V are read as 1 No other commands have any affect on the inputs Switch closures can be read by the digital input by simply connecting the switch between GND terminal and a digital input with the addition of an external 10K pull up resistor to 5Vdc The pull up supplies only 0 5ma therefore self wiping switches designed for low current operation should be used Digital inputs may be used to sense AC voltages by using isolated sensing modules offered by many manufacturers de 5 485 Driver 1 d Watt 150 GMO opto isalator Figure 6 2 Typical Digital Input Circuit Chapter 7 Power Supply DIN 100 modules require a regulated 5Vdc power supply The modules contain a low voltage detection circuit th
36. e cold junction compensation by clearing bit 4 in byte 3 of the setup data RTD Use acalibrated resistor mounted directly on the module connector to avoid lead resistance errors The resistor must be accurate to 0 01 for proper calibration Recommended calibration points are listed in Table 9 1 Follow the command sequence described for voltage inputs to calibrate the module Due to the nonlinear nature of RTD s it may be necessary to repeat the TS command to obtain the desired output Table 9 1 Calibration Values Model Input Stimulus Output Data DIN 110 9000uV 09000 00 DIN 111 90mV 00090 00 DIN 112 900mV 00900 00 DIN 113 4 5V 04500 00 DIN 114 9V 09000 00 DIN 115 90V 00090 00 DIN 125 20 00020 00 DIN 131 39 13 00700 00 DIN 132 41 269mV 01000 00 DIN 133 17 816mV 00350 00 DIN 134 68 783 01000 00 DIN 135 17 445 01500 00 DIN 136 15 576mV 01500 00 DIN 137 10 094mV 01500 00 DIN 138 33 442mV 01982 00 DIN 141 300 000 00558 00 DIN 142 300 000 00547 60 DIN 143 134 910 00115 00 DIN 145 206 10 00090 00 DIN 146 30180 00140 00 DIN 151 25mV 00025 00 DIN 152 25mV 00025 00 DIN 153 90mV 00090 00 DIN 154 90mV 00090 00 DIN 161 18Khz 18000 00 Chapter 10 Extended Addressing The DIN 100 may be configured to a special command format called Extended Addressing This mode uses a different prompt either or to distinguish it from the regular command syntax The major difference in
37. ecifications PARITY ERROR A parity error can only occur if the module is setup with parity on see Setup Usually a parity error results from a bit error caused by interference on the communications line Random parity errors are usually overcome by simply repeating the command If too many errors occur the communications channel may have to be improved or a slower baud rate may be used A consistent parity error will result if the host parity does not match the module parity In this situation the easiest solution may be to change the parity in the host to obtain communication At this point the parity in the module may be changed to the desired value with the SetUp SU command The parity may be changed or turned off by using Default Mode SYNTAX ERROR SYNTAX ERROR will result if the structure of the command is not correct This is caused by having too few or too many characters signs or decimal points missing or in the wrong place Table 4 1 lists the correct syntax for all the commands VALUE ERROR This error results when an incorrect character is used as a numerical value Data values can only contain decimal digits 0 9 Hex values used in the SetUp SU and Digital Output DO commands can range from O F Command Set 4 14 WRITE PROTECTED All commands that write data into nonvolatile memory are write protected to prevent accidental erasures These commands must be preceded with a Write Enable WE command or else a WR
38. efeeds are transmitted When using the command prompt the linefeed characters are not included in the checksum calculation Parity Bits 5 and 6 select the parity to be used by the module Bit 5 turns the parity on and off If bit 5 is 0 the parity of the command string is ignored and the parity bit of characters transmitted by the module is set to 1 If bit 5 is 1 the parity of command strings is checked and the parity of characters output by the module is calculated as specified by bit 6 If bit 6 is 0 parity is even if bit 6 is 1 parity is odd If a parity error is detected by the module it will respond with a PARITY ERROR message This is usually caused by noise on the communications line If parity setup values are changed with the SU command the response to the SU command will be transmitted with the old parity setup The new parity setup becomes effective immediately after the response message from the SU command Baud Rate Bits 0 3 specify the communications baud rate The baud rate can be selected from ten values between 300 and 38400 baud Refer to Table 5 2 for the desired code The baud rate selection is the only setup data that is not implemented directly after an SU command In order for the baud rate to be actually changed a module reset must occur A reset is performed by sending a Remote Reset RR command see Communications or powering down This extra level of write pro
39. er imposed on a DC value the input may be AC coupled by simply placing a capacitor in series with the IN terminal The module contains an internal 1MQ resistor connected from the IN to 2 5V for biasing A 01 uf cap may be used for frequencies down to 10HZ Appendix C DIN 140 Data Sheet SPECIFICATIONS Typical 25 C V 5V RTD Types 00385 00388 00392 1000 0 C Resolution 0 1 Accuracy 0 3 C Input connections 2 3 or 4 wire Excitation current 25 mA Max Lead resistance 50Q Input protection to 120Vac Automatic linearization and lead compensation Lead resistance effect 3 wire 2 5 C per Q of imbalance 4 wire Negligible Sensor Hookups The RTD sensor must be connected as shown in the accompanying diagrams to insure proper operation 3 Wire The DIN 140 modules are shipped from the factory configured for 3 wire operation Connect the RTD sensor as shown in the diagram The wires connected to the and I terminals should be matched in length and gauged for proper lead compensation The and SENSE terminals must be tied together the connector with a short wire jumper For proper 3 wire lead compensation the RTD 3 4 wire set up bit must be 0 see Set Up SU command A typical set up for 3 wire operation would be 31070182 RTD J3 Wire Jumper Figure C 1 3 wire RTD Configuration 4 Wire For 4 wire operation connect the RTD as shown in the diagram If the RTD has heavy excitation wi
40. ex value of the digital input status The number of digital inputs varies depending on module type Digital Inputs 015 DIS DI2 DH DIO Data Bits 5 4 3 2 1 0 For example A typical response from a 101 command could be OOFE This response indicates that DIO 0 and all other digital inputs are 1 All digital inputs that are not implemented or left unconnected are read as 4 Digital input O serves a dual function It is both a digital input and the Event Counter input When reading digital inputs with a checksum be sure not to confuse the checksum with the data Digital Output DO The DO command controls eight bits of digital outputs on the DIN 172 module connector The number of digital outputs implemented depends on the model used The digital outputs allow the module to control external circuits under host command The DO command requires an argument of two hex characters specifying the eight bits of output data Digital Outputs DO7 DO6 DOS DO4 DO DOO Data Bits 7 6 5 4 3 2 1 0 The electrical implementation of the digital output consists of open collector transistors wired to the module connector If a digital output is set to 1 the corresponding transistor is turned on and sinks current Note that when a digital output bit is set to 1 the electrical output is near 0 volts If a digital output is set to 0 the corresponding transistor is turned off and sinks no current Assume a module has two di
41. f calibration for a pe riod of about 3 seconds During this time any command sent to the mod ule will result in a busy exception response
42. formation on disabling the Modbus protocol Command 01 06 0000 0000 89 CA Response 01 06 0000 0000 89 CA Function 15 Force Multiple Coils Digital Outputs Modbus Protocol F 9 The Force Multiple Coils function 15 is used to force multiple Modbus output relay coils to a desired ON or OFF state This function is similar in operation to the DIN 100 ASCII digital output command DO in that it updates the status of all available output coils at once The state of each output coil is set ON or OFF according to the digital data value received with the function The digital output bits are referred to as output relay coils in the Modbus protocol The DIN 100 series digital output bit 00 equals Modbus output relay Coil 1 and digital output bit 05 equals output relay Coil 6 DIN 100 series modules with less than eight digital outputs also equate output bit BOO with output relay Coil 1 and count up by one for each additional output bit Thefollowing example can be used to turn on two digital output bits on a DIN 113 module Command 01 OF 0000 0002 00 03 9F 06 Response 01 OF 0000 0002 D40A In the command string 01 isthe slave address 05 isthe Force Single Coil command 00 00 is the starting address of the digital output bits to be changed 00 07 would equal B07 00 02 specifies the number of output relay coils to be changed 00 03 specifies the digital output data value in HI byte LO byte format Note The HI byte will always
43. gital outputs and you wish to turn both outputs on sinking current Set data bit 0 and data bit 1 to 1 Since the module has only two digital outputs all the other bits are don t cares For example this command will turn both outputs Command 1DOFF Response To turn both outputs off you could use the command Command 10000 Response Command Set 4 8 Digital output settings are not stored in nonvolatile memory If a power failure occurs all digital outputs will be 0 upon power up The DO the only means of changing digital outputs There is no software provision to read the state of digital outputs Read Data RD The read data command is the basic command used to read the buffered sensor data The output buffer Figure 2 1 allows the data to be read immediately without waiting for an input A D conversion For example Command 1RD Response 00072 00 Command 1RD Response 1RD 00072 10A4 Since the RD command is the most frequently used command in normal operation a special shortened version of the command is available If a module is addressed without a two letter command the module interprets the string as an RD command Command 1 Response 00072 10 Command 1 Response 1RD 00072 10A4 Remote Reset RR The reset command allows the host to perform a program reset on the module s microprocessor This may be necessary if the module s internal prog
44. he Output Offset Register may be interpreted in several ways The commands that affect this value are Trim Zero TZ and Clear Zero CZ Setup Command SU Each DIN 100 module contains an EEPROM Electrically Erasable Programmable Read Only Memory which is used to store module setup information such as address baud rate parity etc The EEPROM is a special type of memory that will retain information even if power is removed from the module The EEPROM is used to replace the usual array of DIP switches normally used to configure electronic equipment The SetUp command is used to modify the user specified parameters contained in the EEPROM to tailor the module to your application Since the SetUp command is so important to the proper operation of a module a whole section of this manual has been devoted to its description See Chapter 5 Command Set 4 10 The SU command requires an argument of eight hexadecimal digits to describe four bytes of setup information Command 15031070182 Response Command 1SU31070182 Response 1503107018299 Trim Span TS The trim span command is the basic means of trimming the accuracy of a DIN 100 module The TS command loads a calibration factor into nonvola tile memory to trim the full scale output of the signal conditioning circuitry It is intended only to compensate for long term drifts due to aging of the analog circuits and has a useful trim value of 10 of the nominal calibration se
45. he module calculates the temperature output with a fixed cold junction temperature of 0 degrees Celsius This setup is useful for calibrating the module or in cases where remote CJC is used Normally this bitis cleared to 0 Setup amp SetUp Command 5 7 RTD 3 4 Wire this function pertains only to the DIN 140 series of RTD input modules the bit is set to 1 the module provides the correct lead compensation calculation for 4 wire RTD s If the bit is cleared to 0 the module calculates the correct lead compensation for 3 wire RTD s Meas urement errors may result if the module is not setto the correct sensor type This function has no affect on DIN 145 or DIN 146 Thermistor inputs Delay Bits 0 and 1 specify a minimum turn around delay between a command and the module response This delay time is useful on host systems that are not fast enough to capture data from quick responding commands such as RD This is particularly true for systems that use software UART s The specified delay is added to the typical command delays listed in the Software Considerations section of Chapter 3 Each unit of delay specified by bits 0 and 1 is equal to the amount of time required to transmit one character with the baud rate specified in byte 2 For example one unit of delay at 300 baud is 33 3 mS for 38 4 kilobaud the delay is 0 26 mS The number of delay units is selectable from 0 to 6 as shown in Table 5 3 In some systems such as I
46. ic level devices The number of digital outputs available depends on the module type The DIN 170 Digital Input DI command is used to sense the logic levels on the digital input pins DIO DI7 The digital inputs are used to read logic levels generated by other devices They are also useful to sense the state of electro mechanical limit switches The number of digital inputs available varies with the module type SMALL FILTER AUTOZERO AUTOCAL LARGE FILTER NOTE BOLDF ACE COMMANDS Figure 2 1 Analog Input Block Diagram Chapter 3 Communications Introduction The DIN 100 modules has been carefully designed to be easy to interface to all popular computers and terminals All communications to and from the modules are performed with printable ASCII characters This allows the information to be processed with string functions common to most high level languages such as BASIC The ASCII format makes system debugging easy with a dumb terminal This system allows multiple modules to be connected to a communications port with a single 4 wire cable Up to 32 RS 485 modules may be strung together on one cable 122 with repeaters The modules communicate with the hoston a polling system that is each module responds to its own unique address and must be interrogated by the host A module can never initiate a communications sequence A simple command response protocol must be strictly observed to avoid communication
47. in the command message are uppercase char acters All commands consist of uppercase characters only Characters in each response message appear as graphics characters 1 Setthe communications software parity setting to M for MARK parity type and 7 data bits Or utilize any parity type in both the module and software other than NO parity 2 In custom written software routines mask off the most significant bit of each received character to logic 0 Thus forcing the received character to 7 bit ASCII value Chapter 9 Calibration The DIN 100 module is initially calibrated at the factory and has a recom mended calibration interval of one year Calibration constants are stored in the EEPROM and may be trimmed using the Trim Span TS and Trim Zero TZ commands Calibration procedure is as follows Voltage and current inputs clear the output offset register using the Clear Zero CZ command Zero trims are not neccessary due to the built in auto zero function Apply a known calibrated voltage or current to the input of the module The calibrated stimulus should be adjusted to be near 90 ofthe full scale output of the modules for best results The accuracy of the calibrated voltage or current must be better than the rated accuracy of the module which in most cases is 0 02 of full scale Use the Read Data RD com mand to obtain an output reading If the output corresponds to the applied input no calibration is necessary If the o
48. ions error has occurred If a module is setup to provide linefeeds the linefeed characters are not included in the checksum calculation Parity bits are never included in the checksum calculation Table 4 1 DIN 100 Command Set Command Set 4 6 Command and Definition Typical Typical Command Response Message Message prompt DI Read Alarms Digital Inputs 1DI 0003 DO Set Digital Outputs 1DOFF RD Read Data 1RD 00072 00 RS Read Setup 1RS 31070142 RZ Read Zero 1RZ 00000 00 WE Write Enable 1WE Write Protected Commands MBR Set Modbus Address 1MBRO01 E MBD Modbus Disable 1MBD B RR Remote Reset 1RR SU Setup Module 1SU31070142 TS Trim Span TZ Trim Zero DIN 100 User Commands Note that in all command and response examples given below a carriage return is implied after every character string 1TS 00600 00 x 1TZ 00000 00 i Clear Zero CZ The Clear Zero command clears the output offset register value to 00000 00 This command clears any data resulting from a Trim Zero TZ Command 1CZ Response Command 1CZ Response 1 2 8 Digital Input DI The DI command reads the status of the digital inputs on the DIN 171 The response to the DI command is four hex characters representing two bytes of data The second byte contains the digital input data Command 101 Response 0003 Command 101 Response 1DI0003AB Command Set 4 7 The second byte displays the h
49. isable the Modbus protocol Any DIN 100 series module in Modbus mode can be returned to DIN 100 ASCII protocol mode by connecting a jumper wire between module pins GND and Default pin This places the module in Default Mode where the module will only communicate at 300 baud no parity DIN 100 ASCII protocol and answer to any address While in Default mode transmit an MBD command to internally disable the Modbus protocol Following the MBD command a device reset must occur The reset is necessary to activate the DIN 100 ASCII protocol A reset can occur by removing the Default jumper performing a power up reset or by transmit ting a Write Enable WE and Remote Reset RR command sequence After a reset is performed the module is in DIN 100 ASCII protocol mode Modbus Protocol F 11 Command 1MBD Response Command 1MBD Response 1MBD2E Modbus Exception Responses The following standard Modbus exception codes error messages are supported 01 Illegal Function This exception code is generated when the function code is not recognized by the module 02 Illegal Data Address This code is generated when the specified data address in the command is not supported by the module 03 Illegal Data Value This exception code is returned if the command data is out of range for the function 06 Slave Device Busy After the module is reset by power up a RR command or return from Default Mode the module performs an initial sel
50. ite protected to guard against accidental loss of setup data All write protected commands must be preceded by a Write Enable WE command before the protected command may be executed Miscellaneous Protocol Notes The address character must transmitted immediately after the command prompt character After the address character the module will ignore any character below ASCII 23 except CR This allows the use of spaces ASCII 20 within the command message for better readability if desired Command Set 4 3 The length of a command message is limited to 20 printable characters If a properly addressed module receives a command message of more than 20 characters the module will abort the whole command sequence and no response will result If a properly addressed module receives a second command prompt before it receives a CR the command will be aborted and no response will result Response Structure Response messages from the module begin with either an asterisk ASCII 2A or a question mark ASCII 3F prompt The prompt indicates acknowledgment of a valid command The prompt precedes an error message All response messages are terminated with a CR Many commands simply return a character to acknowledge that the command has been executed by the module Other commands send data information following the prompt The response format of all commands may be found in the detailed command description
51. its own unique address so that commands may be directed to the proper unit Module addresses are assigned by the user with the SetUp SU command Printable ASCII characters such as 1 ASCII 31 or A ASCII 41 are the best choices for address characters The address character is followed by a two character command that identifies the function to be performed by the module All of the available commands are listed in Table 4 1 along with a short function definition All commands are described in Chapter 4 Commands must be transmitted as upper case characters Atwo character checksum may be appended to any command message as a user option See Checksum in Chapter 4 All commands must be terminated by a Carriage Return character ASCII 0D In all command examples in this text the Carriage Return is either implied or denoted by the symbol CR Data Structure Many commands require additional data values to complete the command definition as shown in the example commands in Table 4 1 The particular data necessary for these commands is described in full in the complete command descriptions Command Set 4 2 The most common type of data used in commands and responses is analog data Analog data is always represented in the same format for all models the DIN 100 series Analog data is represented as a nine character string consisting of a sign five digits decimal point and two additional digits The string repre
52. l CJC disable DIN 130 series RTD 3 4 wire DIN 140 series Communication delay 0 6 characters Number of displayed digits Large signal filter constant Small signal filter constant Each of these options will be described in detail below For a quick look up chart on all options refer to Tables 5 1 4 Command Syntax The general format for the SetUp SU command is 1SU byte1 byte 2 byte 3 byte 4 Setup amp SetUp Command 5 2 A typical SetUp command would look like 151731070182 Notice that each byte is represented by its two character ASCII equivalent In this example byte 1 is described by the ASCII characters 31 which is the equivalent of binary 0011 0001 31 hex The operand of a SU command must contain exactly 8 hex 0 F characters Any deviation from this format will result in a SYNTAX ERROR The Appendix contains a convenient hex to binary conversion chart For the purposes of describing the SetUp command bit 7 refers to the highest order bit of a byte of data Bit 0 refers to lowest order bit bitnumber 7 6 5 4 3 2 1 0 binary data 0 0 1 1 0 0 0 1 31 hex The SU command is write protected to guard against erroneous changes in the setup data therefore each SU command must be preceded by a Write Enable WE command To abort an SU commandin progress simply send a non hex character an X for example to generate a SYNTAX ERROR and try again CAUTION Care must be exercised in using the SU co
53. large signal time constant is used if the new reading differs from the old by more than 10 0 degrees Previous data New data Filter selected 00100 00 00105 00 small 00100 00 00111 00 large 00100 00 00091 00 small 00100 00 00085 00 large 00050 00 00045 00 small 00050 00 00039 00 large Large Signal Time Constant The large signal filter time constant is specified by bits 3 4 5 of byte 4 It may be specified from 0 no filter to 16 seconds The time constant for a first order filter is the time required for the output to reach 63 of its final value for a step input Setup amp SetUp Command 5 10 Small Signal Time Constant Bits 0 1 2 specify the filter time constant for small signals Its values are similar to the ones for the large signal filter Most sensors can benefit from a small amount of small signal filtering such as T 0 5 seconds In most applications the small signal time constant should be larger than the large signaltime constant This gives stable readings for steady state inputs while providing fast response to large signal changes Table 5 4 Byte 4 Displayed Digits and Filter Time Constants 4 XXXXX 00 DISPLAYED DIGITS DISPLAYED DIGITS XXXXX XX DISPLAYED DIGITS NO LARGE SIGNAL FILTERING 0 25 SECOND TIME CONSTANT 0 5 SECOND TIME CONSTANT 1 0 SECOND TIME CONSTANT 2 0 SECOND TIME CONSTANT 4 0 SECOND TIME CONSTANT 8 0 SECOND TIME CONSTANT 16 0 SECOND TIME CONSTANT NO SMALL SI
54. m version of a command is transmitted to a module a checksum will be appended to the end of the response For example Command 1RD short form Response 00072 10 Command 1RD long form Response 1RD 00072 10A4 A4 checksum Command Set 4 5 Checksum Calculation The checksum is calculated by summing the hexadecimal values of all the ASCII characters inthe message The lowest order two hex digits of the sum are used as the checksum These two digits are then converted to their ASCII character equivalents and appended to the message This ensures that the checksum is in the form of printable characters Example Append a checksum to the command 1DOFF Characters 1 D O F F ASCII hex values 23 31 44 4F 46 46 Sum hex addition 23 31 44 4F 46 46 173 The checksum is 73 hex Append the characters 7 and 3 to the end of the message 1DOFF73 Example Verify the checksum of a module response 1RD 00072 10A4 The checksum is the two characters preceding the CR A4 Add the remaining character values 1 R D 0 0 0 7 2 1 0 2 31 52 44 2B 30 30 30 37 32 2E 31 302 4 The two lowest order hex digits of the sum are A4 which agrees with the transmitted checksum The transmitted checksum is the character string equivalent to the calcu lated hex integer The variables must be converted to like types in the host software to determine equivalency If checksums do not agree a communicat
55. mmand Improper use may result in changing communications parameters address baud rate parity which will result in a loss of communications between the host and the module In some cases the user may have to resort to using Default Mode to restore the proper setups The recommended procedure is to first use the Read Setup RS command to to examine the existing setup data before proceeding with the SU command Byte 1 Byte 1 contains the module channel address The address is stored as the ASCII code for the string character used to address the module In our example command 1SU31070080 the first byte 31 is the ASCII code for the character 1 If our sample command is sent to a module the EEPROM will be loaded with the address 1 which in this particular case remains unchanged To change the module address to 2 byte 1 of the SetUp command becomes 32 which is the ASCII code for the character 2 Now the command will look like this 1SU32070080 When this command is sent the module address is changed from 1 to 2 and will no longer respond to address 1 When using the SU command to change the address of a module be sure to record the new address in a place that is easily retrievable The only way to communicate with a module with an unknown address is with the Default Mode Setup amp SetUp Command 5 3 are six ASCII codes that are illegal for use as an address These codes are 00 0
56. need for externaltrims Modulesratedfor 30mVhaveaninputrangecapability of 60mV Modulesratedfor 100mVhaveaninputrangeof 120mV DIN 150 DataSheet 0 2 EXCITE I PLT EXC ITE Figure D 1 Bridge Circuit Wiring Toperform aninitial offsettrim attach the bridge unitto the module as shownin Figure D 1 Clearoutany previous offsettrims withthe Clear Zero CZ command Applythe desiredzeroconditionto the bridge sensor For aStrain Gage Bridge this wouldbetherelaxedor unstrainedcondition For loadcells the zeroconditioncouldinclude anytareweightdueto aweighing platform orotherattachmentsthatwouldaffectthezerobalance Obtainan initial reading using the Read Data RD command The output data will indicatethe total offsetofthe system Subtractthe offsetvalue fromthe usableinputrangeof your module either 60mVor 120mV Theresultis the maximumusable inputoverhead Ifthe overheadis notsufficientfor your application the bridge mustbetrimmed externally tolowerthe offset to an acceptable value The bridge may be trimmed with a small series resistance oralargeshuntresistancetothe appropriateleg ofthe bridge as shownis Figure D 2 Ifthe initial offsetis acceptable the offset may be trimmedwiththe Trim Zero TZ command DIN 150 DataSheet D 3 EXCITE IN PUT EXCITE 2 Shunt Trim Figure D 2 Bridge Circuit Trim Example 1 A load cell to be used a weighing application is mated to DIN 152 mod
57. nnect modules without losing communications 6 up to 32 modules on one line 122 with repeaters 7 no communications delay due to multiple modules 8 simplified wiring using standard telephone cable RS 485 does have disadvantages Very few computers or terminals have built in support for this new standard Interface boards are available for the IBM PC and compatibles As RS 485 system usually requires an interface The DIN 190 will convert RS 232 signals to RS 485 or repeat RS 485 signals The DIN 190 connected as an RS 485 repeater can be used to Communications 3 3 extend an existing RS 485 network or connect up to 122 modules on one serial communications port RS 485 Multidrop System Figure 3 1 illustrates the wiring required for multiple module RS 485 sys tem Notice that every module has a direct connection to the host system Any number of modules may be unplugged without affecting the remaining modules Each module must be setup with a unique address and the addresses can be in any order All RS 485 modules must be setup for no echo to avoid bus conflicts see Setup Also note that the connector pins on each module are labelled with notations B R G and Y This designates the colors used on standard 4 wire telephone cable Label Color B GND Black V Green Y DATA Yellow This color convention is used to simplify installation If standard 4 wire telephone cable is used it is onl
58. ommunica tions The RS 232 electrical specification is not supported Modbus is a registered trademark of AEG Modicon Inc The Modbus RTU protocol transmits data in 8 bit binary bytes not ASCII To illustrate the data in this document the 8 bit byte is described as two hexadecimal nibbles For example the binary byte value 0101 1101 willbe written as 5D A typical Modbus RTU command may look like this 0104 20000 0001 31CA Remember this command string and others throughout this docu ment are actually transmitted to a module as eight 8 bit binary charac ters The actual format of the data is dependent on the type of command desired The example above is the Modbus Read Input Registers function The 01 is the address of the slave device DIN 100 module being commanded Each slave device must have its own unique address The 04 specifies the Modbus Read Input Registers function This is equivalent to the Read Data command to obtain analog input data Modbus Protocol F 2 The next two characters 00 00 specify the starting address of the registers to be read The first Modicon input register 30001 is addressed as 00 00 Register 30005 is addressed as 00 04 etc The next two characters of this command specify the number of registers to be read including the starting register In this case the two binary characters 00 01 indicates only one register is to be read The final two characters of the comm
59. ot responding to commands Module responds with 1 COMMAND ERROR to every command Characters in each response message appear as graphics characters RS 485 Module is not responding to commands 1 Using a voltmeter measure the power supply voltage at the Vs and GND terminals to verify the power supply voltage is constantly 5Vdc 5 2 Verify using an ohmmeter that there are no breaks in the communications data lines 3 When using a serial communications converter DIN 191 ensure that the communications Baud Rate switch is set to the proper Baud Rate value 4 Confirm software communications settings in Host computer match those values being used by the connected module s 5 Ifthe Baud Rate value being used in the application is greater than 300 Baud and the module will only communicate 300 Baud then make sure that the DEFAULT terminal is not connected to Ground GND 6 Ensure that module RS 485 Data line module terminal pin 7 is connected to the Host RS 485 Data line 7 Ensure that module RS 485 Data line module terminal pin 8 is connected to the Host RS 485 Data line 8 If the problem is not corrected after completing the steps above then connect the module by itself to a Host computer as outlined in Chapter 1 0 under Quick Hook up Start the supplied Utility software and please call the factory for further assistance Module responds with 1 COMMAND ERROR to every command Ensure that characters
60. other commands 100 mS Table 3 1 Response Timeout Specifications The timeout specification is the turn around time from the receipt of a command to when the module starts to transmit a response Data Format All modules communicate in standard NRZ asynchronous data for mat This format provides one start bit seven data bits one parity bit and one stop bit for each character Single Module Connection Figure 1 1 showsthe connections necessary to attach one module to a host Use the Default Mode to enter the desired address baud rate and other setups see Setups RS 485 The RS 485 communications standard satisfies the need for multidropped systems that can communicate at high data rates over long distances RS 485 is similar to RS 422 in that it uses a balanced differential pair of wires switching from 0 to 5V to communicate data RS 485 receivers can handle common mode voltages from 7V to 12V without loss of data making them ideal for transmission over great distances RS 485 differs from RS 422 by using one balanced pair of wires for both transmitting and receiving Since an RS 485 system cannot transmit and receive at the same time it is inherently a half duplex system RS 485 offers many advantages over RS 232C 1 balanced line gives excellent noise immunity 2 can communicate with D1000 modules at 115200 baud 3 communications distances up to 4 000 feet 4 true multidrop modules are connected in parallel 5 can disco
61. pping box DGH strongly recommends that you insure the product for value prior to shipping Items should not be returned collect as they will not be accepted Shipping Address DGH Corporation Hillnaven Industrial Park 146 Londonderry Turnpike Hooksett NH 03106 Chapter 1 Getting Started Default Mode All DIN 100 modules contain an EEPROM Electrically Erasable Program mable Read Only Memory to store setup information and calibration constants The EEPROM replaces the usual array of switches and pots necessary to specify baud rate address parity etc The memory is nonvolatile which means that the information is retained even if power is removed No batteries are used so itis never necessary to open the module case The EEPROM provides tremendous system flexibility since all of the module s setup parameters may be configured remotely through the com munications port without having to physically change switch and pot settings There is one minor drawback in using EEPROM instead of switches there is no visual indication of the setup information in the module It is impossible to tell just by looking at the module what the baud rate address parity and other settings are It is difficult to establish communica tions with a module whose address and baud rate are unknown To overcome this each module has an input pin labeled DEFAULT By connecting this pin to Ground the module is put in a known communications setup called Default Mod
62. puts are register mapped as two 8 bit bytes 16 bits one byte for inputs and one byte for outputs The least significant byte represent the status of up to 8 digital outputs The most significant byte represents the status of up to 8 digital input bits The register contents can be interrogated as 8 bits of digital input data or together as 16 bits of digital inputs and outputs data Exception errors will be generated by the module if attempting to read or write to more than 16 bits The following example can be used to read only the digital input status Command 01 01 0008 0008 BCOE Response 01 01 01FF 11 C8 In the command string 01 is the slave address 01 is the Read Coil Status command 00 08 is the starting coil number 00 08 is the number of bits to read BC OE is the CRC to this message In the response string 01 is the slave address 01 is the Read Coil Status command 01 is the number of data bytes returned FF is the Digital Inputs status data 11 C8 is the CRC for this message The following example can be used to read the status of both the digital inputs and outputs Command 01 01 00 00 00 10 3D C6 Response 01 01 02 09 FF FF EC In the command string Modbus Protocol F 6 01 is the slave address 01 is the Read Coil Status command 00 00 is the starting coil address 00 10 is the number digital bits to read 3D C6 is the CRC to this message In the response string 01 is the slave address 01 is the Rea
63. r themodule sinternal microprocessor constantly monitors the actual excitation voltage andprovides compensationforany deviation fromthe nominal value Thisresultsinaconstantdata outputfor aconstantbridgeloadevenifthe excitation changes From a user s point ofview the excitation voltage willappearto be exactly 10Vor 5V Calibration Sincethe DIN 150 modules use aratiometrictechniquetocompensatefor variances inthe excitation voltage special consideration is required to properly calibrate the unit Figure D 3 shows the calibration setup The Digital Voltmeter DVM must be capable of measuring the excitation voltage to 4 digit accuracy The voltage source mustbe able to provide millivoltsignalsaccurateto 5microvolts The resistive divider may be constructed from 1 resistors of equal value from 100to 1000 Q The resistordividerplacesthe voltagesourceinthecenterofthe common mode range oftheinputamplifierfor bestaccuracy DIN 150DataSheet 0 6 EXCITE EXCITE Cara ca Gy eae Voltage Source Figure D 3 DIN 150 Calibration Step 1 power up the unit under test and letitwarm up for atleast two minutes Step 2 setthevoltage source to 0 volts short PerformaTZ 00000 00 Trim Zero commandto eliminate any common mode offseterrors Step3 measuretheexcitationvoltage withthe DVM Dividetheresultbythe nominalexcitation voltage either 10V or5V toobtaina compensation factor CF Step 4 calculate
64. rain Gage andotherresis tive bridge devices to an RS 485 computer port Each module contains excitation an instrumentation amplifier and a smart analog to digital convertertoconvertresistivebridge sensorsignalsto ASCII data Theusershouldbecome familiar with the generic DIN 100 information described in the DIN 100 User s Manual before attempting any ofthe proceduresoutlinedbelow Data Format TheASClIloutputdatais expressedin millivolts with 1 0 microvoltresolution For Example Command 1RD Read Data Response 00012 34 Inthiscase theoutputdatais 12 34 millivolts Modulesthatareconfiguredfor 30mVandhaveausablespanof 60mV Modulesconfiguredfor 100mVhaveausablespanof 120mV Theextra overheadisusedtotrimany bridge offsets Setup Data The factory setup forall versions of DIN 150 modulesis310701C2 Sensor Connections See Figure 1 forthe proper bridge sensor connections Shields or grounds shouldbeconnectedtothe Excitation terminal Offset Trim The DIN 150 modules do notprovide any means oftrimming the analog offsetofthe sensorbridge However sensoroffsets maybe nulledfromthe outputdatawith the Trim Zero TZ command This methodoftrimmingis convenientbecause the offsetmay betrimmedthroughthecommunications portatany time Thereisnoneedtohave accesstothe modulesincethe trimmingis performed remotely Theinputsignalconditioning circuitry ofthe DIN 150 modules have awide inputrange to accommodate large sensor offsets withoutthe
65. ram is disrupted by static or other electrical disturbances Once a reset command is received the module will recalibrate itself The calibration process takes approximately 3 seconds For example Command 1RR Response Command 1RR Response 1RRFF In general the state of the digital outputs and the event counter will not be affected by the RR command However if data in the microprocessor s RAM Random Access Memory has been lost the RR command will result in a full power up reset Any commands sent to the module during the self calibration sequence will result in a NOT READY error Command Set 4 9 Read Setup RS The read setup command reads back the setup information loaded into the module s nonvolatile memory with the SetUp SU command The response to the RS command is four bytes of information formatted as eight hex characters Command 1RS Response 31070142 Command 1RS Response 1RS3107014292 The response contains the module s channel address baud rate and other parameters Refer to the setup command SU and Chapter 5 for a list of parameters in the setup information When reading the setup with a checksum be sure not to confuse the checksum with the setup information Read Zero RZ The Read Zero command reads back the value stored in the Output Offset Register Figure 2 1 Command 1RZ Response 00000 00 Command 1RZ Response 1 7 00000 00 0 The data read back from t
66. required to begin using your DIN 100 module We recom mend that you begin to get familiar with the module by setting it up on the bench Start by using a dumb terminal or a computer that acts like a dumb terminal Make the connections shown in the quick hook up drawings Figures 1 1 or 1 2 Put the module in the default mode by grounding the Default terminal Initialize the terminal communications package on your computer to put it into the terminal mode Since this step varies from computer to computer refer to your computer manual for instructions Begin by typing 1RD and pressing the Enter or Return key The module will respond with an followed by the data reading at the input The data includes sign seven digits and a decimal point For example if you are using a thermocouple module and measuring room temperature your reading might be 00025 00 The temperature reading is scaled in which has been preset at the factory Once you have a response from the module you can turn to the Chapter 4 and get familiar with the command set All modules are shipped from the factory with a setup that includes a channel address of 1 300 baud rate no linefeeds no parity alarms off no echo and two character delay Refer to the Chapter 5 to configure the module to your application SUPPLY BMD TB5WDE a DATAZ D el DEFAULT 7 INPUT INFUT Figure 1 1 RS 485 Quick Hook Up Getting Started 1 3 RS 485 Qui
67. res they should be connected to the 1 and terminals For proper 4 wire operation the RTD set up bit must be set to 1 see Set Up SU command A typical set up for 4 wire operation would be 31071182 SENSE SENSE lead Figure 2 4 Wire RTD Configuration 2 Wire The 2 wire connection requires two jumpers on the connector J1 amp J2 as shown in the diagram This connection provides no lead compen sation The RTD set up bit can be either 0 or 1 for this connection J1 J2 Wire Jumper RTD J1 Figure 3 2 Wire Configuration Start Up During normal operation the RTD lead resistance is periodically scanned and filtered by the DIN 140 module This may result in large initial errors if the RTD sensor is connected while the DIN 140 is powered up To avoid this error the sensor should be wired to the connector before power is applied The error may also be eliminated by performing a Remote Reset RR command Lead Resistance Overload If the lead resistance exceeds 500 the output data is set to 99999 99 Sensor Grounding The sensor inputis electrically isolated from the power and communications inputs for common mode voltages up to 500V If the sensor is to be grounded or shielded the ground connection should be made to the I terminal Appendix D DIN 150 Data Sheet The DIN 150 Bridge Sensor Interface Modules contain all of the signal conditioningfunctions necessaryto interface St
68. rity of the response data The command prompt may be used with any command For example Command Set 4 4 Command 1RD short form Response 00072 10 Command 1RD long form Response 1RD 00072 10A4 A4 checksum Checksum Checksum is a two character hexadecimal value appended to the end of a message It verifies that the message received is exactly the same as the message sent The checksum ensures the integrity of the information communicated Command Checksum A two character checksum may be appended to any command to the module as a user option When a module interprets a command it looks for the two extra characters and assumes that itis a checksum If the checksum is not present the module will perform the command normally If the two extra characters are present the module calculates the checksum for the message If the calculated checksum does not agree with the transmitted checksum the module responds with a BAD CHECKSUM error message and the command is aborted If the checksums agree the command is executed If the module receives a single extra character it responds with SYNTAX ERROR and the command is aborted For example Command 1RD no checksum Response 00072 10 Command 1RDEB with checksum Response 00072 10 Command 1RDAB incorrect checksum Response 21 BAD CHECKSUM Command 1RDE one extra character Response 1 SYNTAX ERROR Response Checksums If the long for
69. rror checking value If an error occurs an exception code will be generated The supported master function codes are discussed below 01 Read Coil Status Digital Inputs 04 Read Input Register Analog Inputs 05 Force Single Coil Digital Output 06 Preset Single Register Return to ASCII protocol 15 Force Multiple Coils Digital Outputs Function 01 Read Coil Status Digital Inputs Modbus function 01 Read Coil Status will read the status of both the digital inputs and digital outputs Digital outputs are read as the state of the data on the microprocessor output port before being buffered by the open collector transistor If the coil status of a digital output returns as 1 this means that this particular bit coil is turned or sinking current on the corresponding module digital output pin Depending on the module type some of the digital outputs may not be implemented Modbus relay input coils are considered digital inputs on the DIN 100 series modules Modbus relay output coils are considered digital outputs on the DIN 100 series modules This function can be used to read status of the digital inputs or the combined status of both the digital inputs and digital outputs Modbus Protocol F 5 DIN 100 digital output bits BOO to B05 correspond to Modbus coils 00 00 to 00 05 DIN 100 digital input bits BOO to B05 correspond to Modbus coils 00 08 to 00 OD The DIN 100 series digital inputs and out
70. s collisions and data errors Communications to the DIN 100 modules is performed with two character or three character ASCII command codes such as RD to Read Data from the analog input A complete description of all commands is given in the Chapter 4 A typical command response sequence would look like this Command 1RD Response 00123 00 command response sequence is not complete until a valid response is received The host may not initiate a new command until the response from a previous command is complete Failure to observe this rule will result in communications collisions A valid response can be in one of three forms 1 a normal response indicated by a prompt 2 an error message indicated by a prompt 3 a communications time out error When a module receives a valid command it must interpret the command perform the desired function and then communicate the response back to the host Each command has an associated delay time in which the module is busy calculating the response If the host does not receive a response in an appropriate amount of time specified in Table 3 1 a communications time out error has occurred After the communications time out it is as sumed that no response datais forthcoming This error usually results when an improper command prompt or address is transmitted The table below lists the timeout specification for each command Communications 3 2 Mnemonic Timeout DI DO RD 10 mS All
71. sents a decimal value in engineering units Examples 12345 68 00100 00 00072 10 00000 00 When using commands that require analog data as argument the full nine character string must be used even if some digits are not significant Failure to do this results in a SYNTAX ERROR Analog data responses from the module will always be transmitted in the nine character format This greatly simplifies software parsing routines since all analog data is in the same format for all module types In many cases some of the digits in the analog data may not be significant For instance the DIN 130 thermocouple input modules feature 1 degree output resolution A typical analog data value from this type of module could be 00123 00 The two digits to the right of the decimal point have no significance in this particular model However the data format is always adhered to in order to maintain compatibility with other module types The maximum computational resolution of the module is 16 bits which is less than the resolution that may be represented by an analog data variable The Digital Input Digital Output and Setup commands use hexadecimal representations of data The data structures for these commands are detailed in the command descriptions Write Protection Many of the commands listed in Table 4 1 are under the heading of Write Protected Commands These commands are used to alter setup data in the module s EEPROM They are wr
72. t at the factory It is not to be used to change the basic transfer function of the module Full information on the use of the TS command may be found in Chapter 9 Command 1 5 00500 00 Response Command 175 00500 00 Response 1 5 00500 00 0 Caution TS is the only command associated with the span trim There is no provision to read back or clear errors loaded by the TS command Misuse of the TS command may destroy the calibration of the unit which can only be restored by using laboratory calibration instruments in a controlled environment An input signal must be applied when using this command Trim Zero TZ The Trim Zero command is used to load a value into the Output Offset Register Figure 2 1 to null out an offset in the output data It may be used to trim offsets created by sensors It may also be used to null out data to create a deviation output Example Assume a DIN 151 bridge input module is being used with a load cell for weight measurement An initial reading of the load cell with no weight applied may reveal an initial offset error Command 1RD Response 00005 00 With no weight applied trim the output to read zero To trim use the TZ command and specify the desired output reading Command 1 7 00000 00 zero output Response Command Set 4 11 With no weight applied trim the output to read zero To trim use the TZ command and specify the desired output reading Command 1 7 00000 0
73. t in that the command is echoed and a checksum is generated along with the other data necessary to complete the response The response prompt is used in all command forms The Extended Address commands use a two character ASCII address each character may be one of 122 legal possibilities Illegal characters are NULL 00 CR 00 24 23 7B and 7E Command examples with Extended Address 01 Command 01 Response Command JO1WE Response 01WE27 Command 01RS Response 31070000 typical Command 01RS Response 01RS31070000BB typical Checksums may be appended to commands Command 01WE78 Response All commands that are available with single byte addressing may be accessed with Extended Addressing and vice versa Appendix A ASCII Table Table of ASCII characters A and their equivalent values in Decimal D Hexadecimal Hex and Binary Claret represents Control function A D Hex Binary D Hex Binary 0 00 00000000 128 80 10000000 1 01 00000001 129 81 10000001 B 2 02 00000010 130 82 10000010 C 3 03 00000011 131 83 10000011 D 4 04 00000100 132 84 10000100 E 5 05 00000101 133 85 10000101 F 6 06 00000110 134 86 10000110 u 7 07 00000111 135 87 10000111 H 8 08 00001000 136 88 10001000 9 09 00001001 137 89 10001001 10 00001010 138 10001010 K 11 OB 00001011 139 8B 10001011 L 12 OC 00001100 140 8 10001100 13 OD 00001101 141 8D 100
74. tection is necessary to ensure that communica tions to the module is not accidently lost This is very important when Setup amp SetUp Command 5 5 changing the baud rate of an RS 485 string For more information on changing baud rate refer to Chapter 3 Let srunthrough an example of changing the baud rate Assume our sample module contains the setup data value of 31070080 Byte 2 is 07 By referring to the SU command chart we can determine that the module is set for no linefeeds no parity and baud rate 300 If we perform the Read Setup command with this module we would get Command 1RS Response 31070080 Let s say we wish to change the baud rate to 9600 baud The code for 9600 baud is 0010 from Table 5 2 This would change byte 2 to 02 To perform the SU command we must first send a Write Enable command because SU is write protected Command 1WE Response Command 1SU31020080 Response This sequence of messages is done in 300 baud because that was the original baud rate of the module The module remains in 300 baud after this sequence We can use the Read Setup RS command to check the setup data Command 1RS Response 31020080 Notice that although the module is communicating 300 baud the setup data indicates baud rate of 9600 byte 2 02 To actually change the baud rate to 9600 send a Remote Reset RR command RR is write protected Command 1WE Response 2
75. the module automatically selects the correct Setup amp SetUp Command 5 9 filer constant after every A D conversion The constant selected depends on the magnitude of the change of the input signal and the setup for the number of digits displayed The microprocessor always keeps the value of the last calculated output to compare to a new data conversion If the new data differs from the last output by more than ten counts ofthe last displayed digit the large signal time constant is used in the digital filter If the result of the most recent A D conversion differs from the last output value by less than ten counts of the last displayed digit the small signal time constant is used Let s look at an example The DIN 141 RTD module has a standard output resolution of 0 1 degrees The standard number of displayed digits setup for this module is 6 digits from byte 4 ofthe setup data Therefore the large signal filter will be selected if a new input conversion differs from the previous value by gt 1 0 degree Previous data New data Filter selected 00100 00 00100 50 small 00100 00 00101 50 large 00100 00 00099 90 small 00100 00 00098 90 large 00050 50 00050 00 small 00050 50 00060 00 small Ifthe number of displayed digits is changed to reduce output resolution filter selection is also affected If the number of displayed digits in the previous example is changed to 5 the output resolution becomes 1 0 degree In this case the
76. thecorrectcalibration voltage to apply tothe unit For 30mV units the voltageis V 50mV X CF For 100mV units the voltageis V 100mV XCF SetthevoltagesourcetothecalculatedvoltageV Step 5 trimthe unitwiththe Trim Span TS command For 30mV modulesthecommandis 1TS 00050 00 For 100mVmodulesthecommandis 1TS 00100 00 Step6 verifythetrimusingthe 1RDcommand Theresultshouldbe either 00050 00or 00100 00 Calibration Example Wewishtocalibrate aDIN 151 module This unitcontains5V excitation and a 30mVinput Step 1 isstraightforwardand needs nofurther explanation Step2 setthevoltagesourcetoO volts Trim zero Command 1WE Response DIN 150DataSheet 0 7 DIN 150DataSheet 0 8 Command 1TZ 00000 00 Response Step3 measuretheexcitation voltage withthe DVM Inthis examplethe measuredvoltageis4 954V Calculatethe compensation factor CF 4 954 5 0 9908 Step 4 calculate the calibration voltage V 50mV X0 9908 49 54mV Setthevoltagestandardto 49 54mV Step5 performthe TrimSpancommand Command 1WE Response Command 1TS 00050 00 Response Step6 verifythecalibration continuingto apply 49 54 totheinput Command 1RD Response 00050 00 Thespantrimis nowcomplete The Trim Zero TZ commandmay be used totrimsensoroffsets withoutaffectingthe spantrim Appendix E DIN 100 Specifications Specifications typical 25 C and nominal power supply unless otherwise noted Analog Single ch
77. ule Theloadcellisratedfor3mV V whichresultsinamaximum 30mV with 10V excitation However inthis application the load cellis usedonly intensionsoitsidealoutputwillbefrom 0to 30mV Theloadcellis mountedinpositionwith the weighing attachments Clear any offsetdatathat may be storedinthe DIN 152 module Command 1WE CZ is write protected Response Command 1CZ Clear Zero Response Verifythatthe Zero Trimis cleared Command 1RZ Read Zero Response 00000 00 Obtainaninitialoffsetreadingfromtheloadcellwith noweightattached Command 1RD Read Data Response 00002 34 DIN 150DataSheet 0 4 The initial offset is 2 34mV The DIN 152 has a useful input range of 60mV Aftersubtracting the offsetthe inputoverhead is 62 34mV and 57 66mV TheexpectedO0to 30mV outputoftheloadcelleasilyfallswithin the overheadrangeandnoexternaltrimming is necessary ToTrim Zero Command 1WE TZ is write protected Response Command 1TZ 00000 00 zero output Response Nowreadthe dataoutputto verify thetrim Command 1RD Read Data Response 00000 00 Theloadcellsystemhasbeentrimmedto zero Example 2 Astrain gage bridge willbe usedtomeasurebothcompression andtensile strains onastructuralmember ThebridgeisattachedtoaDIN 152module andthe idealoutputfromthebridgeis 30mVfullscale Clearthe Zero Trim Command 1WE Response Command 1CZ Clear Zero Response Measure theinitial offsetfromthe
78. us Protocol Specifiy the correct Modbus slave address and press the APPLY to transmit the new setup values Once the values have been transmitted press the lt ESC gt key back to the program main menu 7 Remove the connection between Default and GND which performs internal reset to enable Modbus RTU mode If there was no connection between Default and GND then cycle the power on device to force a reset and enable Modbus Mode The device is now configured for Modbus RTU mode and can be connected Modbus Protocol F 4 to a RS 485 based Modbus master system MODBUS Function Codes Modbus protocol compatible devices communicate using a master slave technique similar to that used in ASCII protocol In a master slave commu nications system only one device the master can initiate a communications sequence All others devices the slaves respond when requested by the master Typical master devices can be personal computers or PLCs Typical slave devices are DIN 100 modules The master can address any slave device Slave devices return a message to any command that was addressed specifically to them The returned messages are considered response messages The Modbus protocol format used by a master consists of a device address acommand function code which defines the operation to be performed data required with the command and an error checking value The slave response message contains any required data and an e
79. ustersis DE Control GND Figure B 1 DIN 161 Input Signal Conditioning Block Diagram The input signal is applied to a precision comparator through the Input Input protection is provided to withstand inputs up to 230Vac The compara tor output is then fed through an opto isolator to the module s microproces sor for scaling and formatting The input section is completely isolated from the power and communications lines The isolation allows up to 500V of common mode voltage between the input ground and the power connec tions The input comparator employs hysteresis to provide reliable readings with noisy or slow input signals The amount of hysteresis may be controlled by connecting the hysteresis control line HYSTR to ground or the 2 5V terminal through an external resistor Figure 2 shows the most frequently used connection DIN 160 Data Sheet B 3 Figure B 3 Controlling Hysteresis For Bipolar Signals Figure B 4 Controlling Switching Level and Hysteresis R V Switching hysteresis Open 2 5 0 5 1 7V 5mV For V gt 5 and 0 5V hysteresis 34 V R in KQ x hysteresis 0 5 2 14 switching 17 The hysteresis control may also be connected to ground GND which produces another set of switching levels This connection is shown in figure B 4 If the HYSTR terminal is shorted to GND the nominal switching point is 1 6V with 5mV of hysteresis To measure AC signals sup
80. ut Range 1Hzto20KHz Resolution 0 005960f reading 0 01Hz 0 01 ofreading 0 01 2 20 DIN 170 Digital Inputs Outputs 6 digital inputs or 6 output bits Input voltage levels 0 30V without damage Input switching levels High 3 5V min Low 1 0 max Outputs Open collector to 30V 100mA max load Vsat 1 0V max 100mA Inputs Outputs are read set in parallel solated from power supply ground DIN 190 RS 232 485 Converter Repeater Baud Rates 300 115200 Dip switch selectable Termination and biasing resistors included selectable via internal jumpers Appendix F Modbus Protocol MODBUS PROTOCOL OVERVIEW This document describes the Modbus RTU protocol option included in the DIN 100 series of data acquisition modules This implementation of the Modbus protocol is a subset of the protocol as described in the Modicon Modbus Protocol Reference Guide PI MBUS 300 Rev F Only the RTU version of the protocol has been implemented Modbus RTU mode communicates in standard NRZ asynchronous format with one start bit eight data bits one parity bit and one stop bit Even and odd parity is supported If no parity is specified the number of stop bits can be user configured for either one or two stop bits Baud rates supported at this time are 300 600 1200 2400 4800 9600 19 200 and 38 400 Modbus uses the RS 485 electrical specification for multidrop c
81. utput is in overload check the circuit connections or use a different input value to obtain an output within the operating range of the module To trim the output use the Trim Span TS command The argument of the TS command should correspond to the desired module output After per forming the TS command verify the trim with the RD command For example to trim a DIN 112 module 1 Clear the output offset register Command 1WE Response CZ is write protected Command 1CZ Response 2 Apply an input voltage near 90 of rated scale In this case we use a 900 input voltage accurate to at least 0 02 Obtain an output reading Command 1RD Response 00900 30 In this case the output the module is off by 300uV To trim Command 1WE Response TS is write protected Command 1TS 00900 00 Response This sequence will trim the output to 00900 00 Verify Command 1RD Response 00900 00 The module is calibrated Calibration 9 2 Thermocouples Disable the cold junction compensation by setting bit 4 in byte 3 of the setup data with the SetUp SU command The module may now be calibrated using a known input voltage Perform the calibration as described for a voltage input module Table 9 1 gives recommended calibra tion points Due to the nonlinear nature of thermocouples it may be neces sary to repeat the TS command to obtain the desired output After calibration is complete enable th
82. y necessary to match the labeled pins with the wire color to guarantee correct installation DATA on the label is the complement of DATA negative true To minimize unwanted reflections on the transmission line the bus should be arranged as a line going from one module to the next Tree or random structures of the transmission line should be avoided When using long transmission lines and or high baud rates the data lines should be termi nated at each end with 200 ohm resistors Standard values of 180 ohms or 220 ohms are acceptable During normal operation there are periods of time where all RS 485 drivers are off and the communications lines are in an idle high impedance condition During this condition the lines are susceptible to noise pickup which may be interpreted as random characters on the communications line To prevent noise pickup all RS 485 systems should incorporate 1K ohm bias resistors as shown in Figure 3 1 The resistors will maintain the data lines in a mark condition when all drivers are off DIN 191 and DIN 192 modules have the 1 resistors built in Special care must be taken with very long busses greater than 1000 feet to ensure error free operation Long busses must be terminated as de scribed above The use of twisted cable for the DATA and lines will greatly enhance signal fidelity Use parity and checksums along with the Communications 3 4 form of all commands to detect transmission

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