F2-04RTD 4-Channel RTD Input
Contents
1. Wiring Diagram The F2 04RTD module has a removable connector to make wiring easier Simply 2 squeeze the top and bottom retaining clips and gently pull the connector from the A module cc A Wiring Diagram om ic IN RTD ws Note 1 O TEMP O Chi 200 mA oe G Chi Current Ch2 gt Source Z amp Ch2 S F2 04RTD C Q C 2 Ref Ch3 amp Adj Ch a Note2 ch i 2 ote i Ch4 mi i A D te lL 200 mA Current Source F2 04RTD a A Notes 1 The three wires connecting the RTD to the module must be the same type and length Do not use the shield or drain wire for the third connection 2 If the RTD sensor has four wires the plus sense wire should be left unconnected as shown DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input 6 9 Module Operation D Before you begin writing the control program it is important to take a few minutes to On understand how the module processes and represents the analog signals ae AS Channel The F2 04RTD module can supply different amounts of data per scan depending ox Scanning on the type of CPU you are using The DL230 can obtain one channel of data per 29 Sequence for a CPU scan Since there are four channels it can take up to four2. The DL230 CPU does not have the special V memory locations that allow you to automatically enable the data transfer Since all channels are multiplexed into a single data word the control program must be setup to determine which channel is being read Since the module appears as X input points to the CPU itis very easy to use the active channel status bits to determine which channel is being monitored NOTE DL230 CPUs with firmware release version 1 6 or later required for multiplexing ladder Store Channel 1 X40 X41 X50 LD V40401 ANDD K7FFF OUT V Store Channel 2 X40 X41 X51 V2000 Co A Store Channel 3 X40 X41 X52 Vr FV Store Channel 4 X40 X41 X53 iat X37 CoO SET OUT Vv2001 C1 CRsT X37 Ci ser OUT V2002 C2 RST X37 C2 1 SET OUT V2003 C3 Ast X37 5 SY oe at 2 DU Tw S Loads the complete data word into the accumulator The V memory location depends on the I O configuration See Appendix A for the memory map This instruction masks the sign bit Without this the values used will not be correct so do not forget to include it When X40 X41 and X50 are off channel 1 data is stored in V2000 CO is reset to indicate that channel 1 s value is positive If X37 is on the data value represents a negative
3. Scan N 1 lt Ch1 2 3 4 Scan N 2 lt Ch1 2 3 4 Store data H m Scan N 3 lt Ch 1 2 3 4 y Scan N 4 Ch 1 2 3 4 Write to Outputs Even though the channel updates to the CPU are synchronous with the CPU scan the module asynchronously monitors the analog transmitter signal and converts the signal to a 16 bit binary representation This enables the module to continuously provide accurate measurements without slowing down the discrete control logic in the RLL program The time required to sense the temperature and copy the value to V memory is 160 milliseconds minimum to 640 milliseconds plus 1 scan time maximum number of channels x 160 msec 1 scan time DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input Writing the Control Program D Reading Values There are two methods of reading values O Pointer Method e The pointer method a and Multiplexing e Multiplexing as You must use the multiplexing method when using a DL230 CPU You must also so use the multiplexing method with remote I O modules the pointer method will not work You can use either method when using DL240 DL250 1 and DL260 CPUs z but for ease of programming it is strongly recommended that you use the pointer method Pointer Method The CPU has special V memory locations assigned to each base slot that greatly s J
4. gt OUT Check Channel 2 LD V2002 ANDD K7FFF OUT V2012 V2002 K8000 C2 gt OUT Magnitude Plus Check Channel 1 Sign BCD SP1 LDD SP1 V2000 ANDD K7FFFFFFF OUTD V2010 V2001 K8000 C1 q gt OUT Check Channel 2 LDD V2002 ANDD K7FFFFFFF OUTD V2012 V2003 K8000 C2 gt OUT DL205 Analog Manual 7th Ed Rev B 4 10 Load channel 1 data from V memory into the accumulator Contact SP1 is always on This instruction masks the sign bit of the binary data if itis set Without this step negative values will not be correct so do not forget to include it Put the actual signal value in V2010 Now you can use the data normally Channel 1 data is negative when C1 is on a value of 1 0 reads as 8010 2 0 is 8020 etc Load channel 2 from V memory into the accumulator Contact SP1 is always on This instruction masks the sign bit of the binary data if itis set Without this step negative values will not be correct so do not forget to include it Put the actual signal value in V2012 Now you can use the data normally Channel 2 data is negative when C2 is on a value of 1 0 reads as 8010 2 0 is 8020 etc Load channel 1 data from V memory into the accumulator Remember the data can be negative Con
5. temperature CO is set to indicate that channel 1 s value is negative When X40 is on and X41 and X51 are off channel 2 data is stored in V2001 C1 is reset to indicate that channel 2 s value is positive If X37 is on the data value represents a negative temperature C1 is set to indicate that channel 2 s value is negative When X40 and X52 are off and X41 is on channel 3 data is stored in V2002 C2 is reset to indicate that channel 3 s value is positive If X37 is on then the data value represents a negative temperature C2 is set to indicate that channel 3 s value is negative When both X40 and X41 are on and X53 is off channel 4 data is stored in V2003 C3 is reset to indicate that channel 4 s value is positive If X37 is on the data value represents a negative temperature C3 is set to indicate that channel 4 s value is negative DL205 Analog Manual 7th Ed Rev B 4 10 5 Q ma To Sr N c Lo vi Reading 2 s Complement Values Multiplexing Viviviv 230 240 250 1 260 Scaling the Input Data F2 04RTD 4 Channel RTD Input The DL230 CPU does not have the special V memory locations that allow you to automatically enable the data transfer Since all channels are multiplexed into a single data word the control program must be setup to determine which channel is being read Since the module appears as X input points to the CPU itis very easy to use the acti
6. xX x iv 230 240 250 1 260 F2 04RTD 4 Channel RTD Input Add the following logic to filter and smooth analog input noise in DL250 1 and DL260 CPUs This is especially useful when using PID loops Noise can be generated by the field device and or induced by field wiring The analog value in BCD is first converted to a binary number because there is nota BCD to real conversion instruction Memory location V1400 is the designated workspace in this example The MULR instruction is the filter factor which can be from 0 1 to 0 9 The example uses 0 2 A smaller filter factor increases filtering You can use a higher precision value but it is not generally needed The filtered value is then converted back to binary and then to BCD The filtered value is stored in location V1402 for use in your application or PID loop NOTE Be careful not to do a multiple number conversion on a value For example if you are using the pointer method to get the analog value it is in BCD and must be converted to binary However if you are using the conventional method of reading analog and are masking the first fifteen bits then it is already in binary and no conversion using the BIN instruction is needed Also if you are using the conventional method change the LLD V2000 instruction to LD V2000 ont Loads the analog signal which is a BCD value yeaah and has been loaded from V memory location V2000 int
7. J simplify the programming requirements These V memory locations 230 240 250 1 260 e specify the number of channels to scan e specify the storage locations The example program shows how to setup these locations Place this rung anywhere in the ladder program or in the initial stage if you are using stage programming instructions This is all that is required to read the data into V memory locations Once the data is in V memory you can perform math on the data compare the data against preset values and so forth V2000 is used in the example but you can use any user V memory location In the examples the module is installed in slot 2 You should use the V memory locations used in your application The pointer method automatically converts values to BCD NOTE DL240 CPUs with firmware release version 2 5 or later and DL250 CPUs with firmware release version 1 06 or later support this method Use the DL230 multiplexing example if your firmware revision is earlier verify that the addresses in the CPU are zero SPO LD or LD K 0400 a K 8400 Loads a constant that specifies the number of channels to scan and the data format The upper byte most significant nibble MSN selects the data format 0 BCD 8 Binary the LSN selects the number of channels 1 2 3 or 4 The binary format is used for displaying data on some operator interfaces The DL230 240 CPUs do not support binary math
8. as shown in the following example T SY oo at 34 DU Tw S AN K8000 Load negative value into the accumulator so we Es age can convert it to a positive value INV Invert the binary pattern in the accumulator ADDB Add 1 K1 OUT Save Channel 1 data at V2010 V2010 Repeat for other channels as required You may recall that this module appears to the CPU asa 32 point discrete input module You can use these points to obtain e An indication of which channel is active e The digital representation of the analog signal e Module diagnostic information Since all input points are automatically mapped into V memory it is very easy to determine the location of the data word that will be assigned to the module F2 04RTD N a j gt GLA a ye ye ye aa o H EE eS Sloto Slot1 Slot2 Slot3 Slot4 8pt 8pt 32pt 16pt 16pt Input Input Input Input Output E hai Xo X10 X20 x60 YO S we X7 X17 X57 X77 Y17 C C C C C V40400 V40403 v40402 v40401 MSB LSB MSB LSB PaaS a Bit 15 14131211109 8 765 43 21 0 Bit 15 14131211109 8 7 65 43 210 xX XxxX xX x X X xX 5 54 4 3 32 2 7 07 0 7 07 0 DL205 Analog Manual 7th Ed Rev B 4 10 6 16 F2 04RTD 4 Channel
9. functions whereas the DL250 does OUT Special V memory location assigned to slot 2 that contains the V7662 number of channels to scan This loads an octal value for the first V memory location that will be LDA used to store the incoming data For example the 02000 entered 02000 here would designate the following addresses Chi V2000 V2001 Ch 2 V2002 V2003 Ch 3 V2004 V2005 Ch 4 V2006 V2007 OUT The octal address 02000 is stored here V7672 is assigned to slot V7672 2 and acts as a pointer which means the CPU will use the octal value in this location to determine exactly where to store the incoming data DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input The tables below show the special V memory locations used by the DL240 DL250 1 and DL260 for the CPU base and local expansion base I O slots Slot 0 zero is the module next to the CPU or D2 CM module Slot 1 is the module two places from the CPU or D2 CM and so on Remember the CPU only examines the pointer values at these locations after a mode transition Also if you use the DL230 multiplexing method verify that these addresses in the CPU are zero 5 Q mpe keo Sr A c LO s The Table below applies to the DL240 DL250 1 and DL260 CPU base CPU Base Analog Input Module Slot Dependent V memory Locations Lae Ee ee Ey set TV cee V700 V760 faces VEBE V707 No of Chan
10. 02Cu 200 C to 260 C 328 F to 500 F 25QCu 200 C to 260 C 328 F to 500 F E GaeeD Absolute Maximum Ratings Fault protected input 50 Vdc Converter Type Charge balancing 24 bit Sampling Rate 160 msec per channel Linearity Error End to End 0 05 C maximum 0 01 C typical 1 Channel Scan max 230 CPU RTD Excitation Current 200 uA Common Mode Range 0 5 VDC Notch Filter gt 100dB notches 50 60 Hz f_3aB 13 1 Hz Digital Input Points Required 32 X input points 15 binary data bits 1 sign bit 2 channel ID bits 4 fault bits Power Budget Requirement 90 mA 5 VDC from base Operating Temperature 0 to 60 C 82 to 140 F DL205 Analog Manual 7th Ed Rev B 4 10 PA SY a8 Us DU Tw S 5 Q mpe To Sr N c LO s Special Placement Requirements DL230 and F2 04RTD 4 Channel RTD Input It is important to examine the configuration if you are using a DL230 CPU As you can see in the section on writing the program you use V memory locations to send the analog data If you place the module so that the input points do not start on a V memory boundary the instructions cannot access the data This also applies Remote I O Bases when placing this module in a remote base using a D2 RSS in the CPU slot See the table below Correct F2 04RTD My A A i Lye ye ye ye a T Sito Slott Slot2 Slot3 Slot4 i6p 8
11. F2 04RTD 4 Channel RTD Input In This Chapter Module Specifications Setting the Module Jumpers Connecting the Field Wiring Module Operation Writing the Control Program 6 2 F2 04RTD 4 Channel RTD Input Module Specifications IN RTD The F2 04RTD 4 Channel Resistive Temperature Detector L TEMP Input Module provides several features and benefits e Provides four RTD input channels with 0 1 F resolution l F2 04RTD e Automatically converts type Pt100Q2 jPt100Q Pt10002 Cu 252 Cu10Q signals into direct temperature readings No extra scaling or complex conversion is required e Temperature data format is selectable between F or C magnitude plus sign or 2 s complement e Precision lead wire resistance compensation by dual matched current sources and ratiometric measurements e Temperature calculation and linearization are based on data provided by the National Institute of Standards and Technology NIST aan e Diagnostics features include detection of short circuits and input power disconnection C Y 5 Q mpa To Sr N c LO s Module The module automatically re calibrates every five seconds to remove any offset Calibration and gain errors The F2 04RTD module requires no user calibration However
12. RTD Input Remember when using DL230 CPUs input points must start on a V memory boundary To use the V memory references required for a DL230 CPU the first a input address assigned to the module must be one of the following X locations The A table also shows the V memory addresses that correspond to these X locations oc SE aia Lo i Analog Data Bits The first 16 bits represent the analog data in binary format V40401 Bit Value Bit Value MSB LSB 7 are 1111119876543210 1 2 9 512 2 4 10 1024 de 3 8 11 2048 x Xx 4 16 12 4096 3 data bits 2 5 32 13 8192 7 0 6 64 14 16384 7 128 15 32768 Active The active channel bits represent the Channel multiplexed channel selections in binary V40402 Bits format MSB LSB Bit 1 Bit O Channel 0 0 1 10 0 1 2 xX 1 0 3 ee 4 1 1 4 7 active channel bits i Broken The broken transmitter bits are on when Transmitter the corresponding RTD is open V40402 Bits Bit Channel MSB LSB Pointer and 8 1 Multiplexing 9 2 119876543210 Ladder Methods 10 3 X 10 XX X 11 4 5 54 4 7 07 0 broken transmitter bits DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input 6 17 Reading Magnitude Plus Sign Values Multiplexing SILIS x 230 240 250 1 260
13. e must be the same RTD type The default setting from the factory is Pt100 Q RTD 2 comes with the jumper removed This selects the DIN 43760 European type RTD European curve type RTDs are calibrated to DIN 43760 BS1905 or IEC751 specifications which is 00385 Q Q C 100 C 138 52 The jPt100 Q type is used for the American curve 00392 Q Q C platinum 100 Q RTDs The 10 Q and 25 Q RTD settings are used with copper RTDs DL205 Analog Manual 7th Ed Rev B 4 10 T Sy oo at 234 DU Tw S 6 6 F2 04RTD 4 Channel RTD Input 5 Q mpa keo Sm A c LO Selecting the Conversion Units The table shows how to arrange the jumpers to set the input type X jumper installed empty space jumper removed Jumper Pins OO umee Cu 10 Q Cu 25 Q jPt100 Q Pt100 Q Pt1000 Q Use the last two jumpers Units 0 and Unit 1 to set the conversion unit The options are magnitude sign or 2 s complement in Fahrenheit or Celsius The module comes from the factory with both jumpers installed for magnitude sign conversion in Fahrenheit All RTD types are converted into a direct temperature reading in either Fahrenheit or Celsius The data contains one implied decimal place For example a value in V memory of 1002 would be 100 2 C or F Negative temperatures can be represented in either 2 s complement or magnitude plus sign form If the temperature is negative the most significant bit in the V mem
14. e to the COM terminal Lead Configuration for RTD Sensors The suggested three lead configuration shown below provides one lead to the CH terminal one lead to the CH terminal and one lead to the common terminal Compensation circuitry nulls out the lead length for accurate temperature measurements Some sensors have four leads When making connections do not connect the second lead to the CH input leave that lead unconnected Do not use configurations having only one lead connected to each input There is no compensation and temperature readings will be inaccurate This module has low RTD excitation current worst case dissipation is only 016 mW Wiring Connections For Typical RTD Sensor Black gt ToCH Black To COM Sensor Red gt To CH Red if applicable gt No Connection if sensor has 4 leads only connect one lead to CH The F2 04RTD module has been designed to operate within the ambient temperature range of 0 C to 60 C Precision analog measurement with no long term temperature drift is assured by a chopper stabilized programmable gain amplifier ratiometric referencing and automatic offset and gain calibration DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input
15. if your process requires calibration it is possible to correct the RTD tolerance using ladder logic You can subtract or add a constant to the actual reading for that particular RTD RTD Input The F2 04RTD module requires 32 discrete input points from the CPU The module Configuration can be installed in any slot of a DL205 system including remote bases The limiting Requirements factors on the number of analog modules used are e For local and local expansion systems the available power budget and number of discrete I O points e For remote I O systems the available power budget and number of remote I O points Check the user manual for your particular CPU model for more information regarding the available power budget and number of local local expansion or remote I O points NOTE DL230 CPUs with firmware release version 1 6 or later DL240 CPUs with firmware release 2 5 or later DL250 CPUs with firmware release version 1 06 or later are required for proper operation DL205 Analog Manual 7th Ed Rev B 4 10 Input Specifications F2 04RTD 4 Channel RTD Input The following table provides the specifications for the F2 O4RTD module Review these specifications to make sure the module meets your application requirements Number of Channels 4 differential inputs Input Ranges Pt100 200 C to 850 C 328 F to 1562 F Pt 1000 200 C to 595 C 328 F to 1103 F jPt100 38 C to 450 C 36 F to 842 F 1
16. nels V7660 v7661 V7662 V7663 V7664 V7665 V7666 V7667 v7670 V7671 V7672 V7673 V7674 V7675 V7676 V7677 The Table below applies to the DL250 1 or DL260 expansion base 1 Expansion Base D2 CM 1 Analog Input Module Slot Dependent V memory Locations CEEA The Table below applies to the DL250 1 or DL260 expansion base 2 Expansion Base D2 CM 2 Analog Input Module Slot Dependent V memory Locations Ra Pah an ae aa The Table below applies to the DL260 CPU expansion base 3 s TOP tT 2 Te Ts 8 7 The Table below applies to the DL260 CPU expansion base 4 Expansion Base D2 CM 4 Analog Input Module Slot Dependent V memory Locations pot 2 e Se DRNEA Red ee V PROE VAROS VORoOT No of Channels V36300 V36301 V36302 V36303 V36304 V36305 V36306 V36307 Storage Pointer V36310 V36311 V36312 V36313 V36314 V36315 V36316 V36317 DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input 6 13 Negative With bipolar ranges you need some additional logic to determine whether the Temperature value being returned represents a positive voltage or a negative voltage For P Readings with example you may need to know the direction for a motor There is a simple solution Sq Magnitude Plus e Ifyou are using bipolar ranges and you get a value greater than or J Sign Pointer equal to 8000p the value is negative J3 Method ade e If you get a value les
17. o the accumulator Contact SP1 is always on Converts the BCD value in the accumulator to __ BIN binary Remember this instruction is not needed if the analog value is originally brought in as a binary number Converts the binary value in the accumulator BTOR to a real number Subtracts the real number stored in location SUBR V1400 from the real number in the accumulator V1400 and stores the result in the accumulator V1400 is the designated workspace in this example Multiplies the real number in the Mn accumulator by 0 2 the filter factor and stores the result in the accumulator This is the filtered value Adds the real number stored in _ ADDR location V1400 to the real number V1400 filtered value in the accumulator and stores the result in the accumulator Copies the value in the accumulator to OUTD location V1400 V1400 Converts the real number in the RTOB accumulator to a binary value and stores the result in the accumulator Converts the binary value in the accumulator BCD to a BCD number Note The BCD instruction is not needed for PID loop PV loop PV is a binary number Loads the BCD number filtered value from OUTD the accumulator into location V1402 to use in V1402 your application or PID loop DL205 Analog Manual 7th Ed Rev B 4 10 T Sy oO at 234 3 g TA S
18. ory location is set X17 The 2 s complement data format may be required to correctly display bipolar data on some operator interfaces This data format could also be used to simplify averaging a bipolar signal To view this data format in DirectSoft32 select Signed Decimal The table shows how to arrange the jumpers X jumper installed empty space jumper removed Magnitude Sign oF 2G DL205 Analog Manual 7th Ed Rev B 4 10 Connecting the Field Wiring Wiring Guidelines RTD Resistance Temperature Detector Ambient Variations in Temperature 6 7 F2 04RTD 4 Channel RTD Input Your company may have guidelines for wiring and cable installation If so you should check those before you begin the installation Here are some general things to consider e Use the shortest wiring route whenever possible e Use shielded wiring and ground the shield at the transmitter source Do not ground the shield at both the module and the source e Do not run the signal wiring next to large motors high current switches or transformers This may cause noise problems e Route the wiring through an approved cable housing to minimize the risk of accidental damage Check local and national codes to choose the correct method for your application Pe Sy oo JR US DU Tw S Use shielded RTDs whenever possible to minimize noise on the input signal Ground the shield wire at one end only Connect the shield wir
19. pt 16pt 32pt 8pt D Output Output Input Input Input S a mI yo Y20 xo x20 x60 e Y17 Y27 X17 x57 X67 CI 1 CI 1 Data is correctly entered so input points start on a V40400 V40403 V memory boundary address from the table below 40401 V40402 MSB V40402 LSB MSB V40401 LSB X XX xXx X XX X 5 54 4 3 32 2 7 07 0 7 07 0 Incorrect F2 04RTD M a A N a i Pe Te TA 0 Sloti Slot2 Slot3 Slot4 S 16pt 8pt 16pt 8pt 32pt D SO Output Ottput Input Input Input comm g i Yo Y20 X20 X30 Y17 Y27 X17 X67 C C C C C l Data is split over three locations so instructions cannot access data from a DL230 V40403 MSB LSB MSB VADE LSB MSB V40401 LSB Pe FE A X XX X xX XX X x XX X 7 76 6 5 54 4 3 32 2 7 07 0 7 07 0 7 07 0 To use the V memory references required for a DL230 CPU the first input address assigned to the module must be one of the following X locations The table also shows the V memory addresses that correspond to these X locations DL205 Analog Manual 7th Ed Rev B 4 10 F2 04RTD 4 Channel RTD Input 6 5 Setting the Module Jumper
20. s Jumper Locations Selecting the Number of Channels Setting Input Type Locate the bank of seven jumpers J8 on the PC board Notice that the description of each jumper is on the PC board You can select the following options by installing or removing the jumpers e Number of channels 1 thru 4 e The input type 10 Q ohms or 25 Q copper RTDs jPt 100 Q Pt 100 Q or Pt 1000 2 RTDs e Temperature conversion 2 s complement or magnitude plus sign format in Fahrenheit or Celsius To prevent losing a jumper when it is removed store it near its original location by sliding one of its sockets over a single pin The two jumpers labeled CH 1 and CH 2 are used to select the number of channels that will be used The factory default setting is four channel operation both jumpers installed Any unused channels are not processed For example if you select channels 1 thru 3 channel 4 will be inactive The table shows how to arrange the jumpers to select the number of channels X jumper installed empty space jumper removed Number of Jumper Channels CH 1 CH 2 S CH 1 1 CH 2 RTD O 2 X RTD 1 Jumper RTD 2 Descriptions 3 X Units 0 4 x x Units 1 The jumpers labeled RTD 0 RTD 1 and RTD 2 are used to select the type of RTD The module can be used with many types of RTDs All channels of the modul
21. s than or equal to 7FFFy the value is positive 50g X ViVi Vv x 230 240 250 1 260 The sign bit is the most significant bit which combines 8000 to the data value If the value is greater than or equal to 8000 you only have to mask the most significant bit and the active channel bits to determine the actual data value NOTE DL240 CPUs with firmware release version 2 5 or later and DL250 CPUs with firmware release version 1 06 or later support this method Use the DL230 multiplexing example if your firmware revision is earlier The following two programs show how you can accomplish this The first example uses magnitude plus sign binary and the second example uses magnitude plus sign BCD Since you always want to know when a value is negative these rungs should be placed before any other operations that use the data such as math instructions scaling operations and so forth Also if you are using stage programming instructions these rungs should be in a stage that is always active Note you only need this logic for each channel that is using bipolar input signals The following examples only show two channels DL205 Analog Manual 7th Ed Rev B 4 10 5 Q mpa keo Sm A c LO F2 04RTD 4 Channel RTD Input Magnitude Plus Check Channel 1 Sign Binary 4 SP1 LD SP1 V2000 ANDD K7FFF OUT V2010 V2000 K8000 C1 o a
22. scans to get data for DL230 CPU all channels Once all channels have been scanned the process starts over with Multiplexing channel 1 Unused channels are not processed so if you select only two channels each channel will be updated every other scan The multplexing method can also be used for the DL240 250 1 260 CPUs Scan Read Inputs eee 7 Execute Application Program Read the data ScanN lt _ Channel 1 HI Scan N 1 lt Channel 2 Store data Scan N 2 lt Channel 3 H K Scan N 3 lt j Channel 4 y Scan N 4 lt Channel 1 Write to Outputs DL205 Analog Manual 7th Ed Rev B 4 10 6 10 F2 04RTD 4 Channel RTD Input 5 oN mpa keo Sm A c Lo s Channel Scanning Sequence for a DL240 DL250 1 or DL260 CPU Pointer Method Analog Module Updates If you are using a DL240 DL250 1 or DL260 CPU you can obtain all four channels of input data in one scan This is because the DL240 250 1 260 CPUs support special V memory locations that are used to manage the data transfer This is discussed in more detail in the section on Writing the Control Program Scan y System With Read Inputs DL240 250 1 260 CPU Execute Application Program Read the data Scan N lt Ch 1 2 3 4 H
23. tact SP1 is always on This instruction masks the sign bit of the BCD data if it is set Without this step negative values will not be correct so do not forget to include it Put the actual signal value in V2010 Now you can use the data normally Channel 1 data is negative when C1 is on a value of 1 0 reads as 8000 0010 2 0 is 8000 0020 etc Load channel 2 from V memory into the accumulator Remember the data can be negative Contact SP1 is always on This instruction masks the sign bit of the BCD data if it is set Without this step negative values will not be correct so do not forget to include it Put the actual signal value in V2012 Now you can use the data normally Channel 2 data is negative when C2 is on a value of 1 0 reads as 8000 0010 2 0 is 8000 0020 etc Negative Temperatures 2 s Complement Binary Pointer Method X Viv v 230 240 250 1 260 Understanding the Input Assignments Multiplexing Ladder Only ViVivi iVv 230 240 250 1 260 F2 04RTD 4 Channel RTD Input You can use the 2 s complement mode for negative temperature display purposes while at the same time using the magnitude plus sign of the temperature in your control program The DirectSOFT32 element Signed Decimal is used to display negative numbers in 2 s complement form To find the absolute value of a negative number in 2 s complement invert the number and add 1
24. ve channel status bits to determine which channel is being monitored The 2 s complement data format may be required to correctly display bipolar data on some operator interfaces This data format could also be used to simplify averaging a bipolar signal To view this data format in DirectSOFT32 select Signed Decimal Load Data SP1 LD Loads the complete data word into the accumulator V40401 The V memory location depends on the I O 1 configuration ANDD This instruction masks the channel sign bit K7FFF Store Channel 1 X40 X41 X50 OUT When X40 X41 and X50 are off channel 1 data is Vv2000 stored in V2000 Store Channel 2 X40 X41 X51 OUT When X40 is on and X41 and X51 are off channel 2 VA Vv2001 data is stored in V2001 Store Channel 3 X40 X41 X52 OUT When X40 and X52 are off and X41 is on channel 3 v2002 data is stored in V2002 Store Channel 4 X40 X41 X53 OUT When both X40 and X41 are on and X53 is off channel 1 2003 4 data is stored in V2003 No scaling of the input temperature is required The readings directly reflect the actual temperatures For example a reading of 8482 is 848 2 C a reading of 16386 is 0 2 C magnitude plus sign and a reading of 32770 is 0 2 C 2 s complement DL205 Analog Manual 7th Ed Rev B 4 10 Filtering Input Noise DL250 1 DL260 CPUs Only
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