HART Intelligent Temperature Transmitter TT421
Contents
1. Measured Type Simple Differential Maximum Minimum Average TT421 L3 T4 indicates factory 9Smar Research Corporation 29 TT421MAN 0109 Mechanical Dimensions Below are the mechanical dimensions of the internal transmitter and BUZ enclosure q LY Fig 3 7 Mechanical Dimensions Fig 3 8 TT421 Images Smar Research Corporation 30 TT421MAN 0109 Smar Research reserves the right to make changes to design and functionality of any product without notice Smar Research does not assume any liability arising out of the application or use of any product Smar Research Technology Source and the SRC logo are registered trademarks of Smar Research Corporation The HART Fieldbus and Profibus Foundation logos are trademarks of their respective owners Smar Research Corporation 2110 Fifth Avenue Ronkonkoma NY USA 11779 Tel 631 737 3111 Fax 631 737 3892 techinfo SmarResearch com www SmarResearch com HART f Omar Research Corporation 31 TT421MAN 01092. 0 Ohms 10 Ohms you must change the settings as UPPER VALUE 20 mA 100 Ohms follows and you want to change the settings to a Set the LOWER VALUE 90 i e 100 10 b Set the UPPER VALUE 0 Ohms LOWER VALUE 4 mA 100 Ohms c Set the LOWER VALUE 100 Ohms UPPER VALUE 20 mA 20 Ohms Smar Research Corporation 18 TT421MAN 0109 Re ranging to Applied Input This is the most conventional way to re range or to calibrate a transmitter Apply the input to which you want to set the 4 mA PV 0 point If through the HPC301 Hand Held Terminal you tell the transmitter that this is the 4 mA PV 0 point this input is set as the Lower Value and the span is maintained The same procedure is applied for the Upper Value Example A transmitter with resistance input is ranged so that LOWER VALUE 0Ohm UPPER VALUE 100 Ohm After installation the potentiometer residual may give a reading of for instance 5 Ohm when the re sistive position indicator is at zero The zero suppression is easily accomplished with the re ranging with reference The Lower Value is the transmitter reading of the applied input The Upper Range Value may be changed in the same way As mentioned before the transmitter reading in Engineering Units of the 4 20 mA points may differ slightly from your plant standard Although the 4 20 mA setpoints will operate properly within these applied settings the transmitter reading in Engineering Units may indicate a slightly dif
3. 1 320 to 320 576 to 576 5 0 5 Pt50 IEC 200 to 850 328 to 1562 10 0 2 1050 to 1050 1890 to 1890 10 1 0 RTD Pt100 IEC 200 850 328 to 1562 10 0 2 1050 to 1050 1890 to 1890 10 1 0 Pt500 IEC 200 to 450 328 to 842 10 0 2 NA NA NA NA Pt50 200 to 600 328 to 1112 10 0 25 800 to 800 1440 to 1440 10 1 0 Pt100 JIS 200t0600 328to 1112 10 0 25 800 to 800 1440 to 1440 10 1 5 Pt1000 IEC 200 to 300 328 to 572 10 0 25 500 to 500 868 to 500 10 1 5 B NBS 100 to 1800 212 to 3272 50 30 5 1700 to 1700 3060 to 3060 60 t1 0 NBS 100 to 1000 148 to 1832 20 10 2 1100 to 1100 1980 to 1980 20 1 0 J NBS 150 to 750 238 to 1382 30 0 3 900 to 900 1620 to 1620 30 0 6 lt NBS 200 to 1350 328 to 2462 60 0 6 1550 to 1550 2790 to 2790 60 1 2 COUPLE NBS 100 to 1300 148 to 2372 50 20 5 1400 0 1400 2520 to 2520 50 1 0 R NBS 0 to 1750 32 to 3182 40 0 4 1750 to 1750 3150 to 3150 40 2 0 S NBS 0 to 1750 32 to 3182 40 0 4 1750 to 1750 3150 to 3150 40 2 0 T NBS 200 to 400 328 to 752 15 0 15 600 to 600 1080 to 1080 15 0 8 L DIN 200 to 900 328 to 1652 35 0 35 1100 to 1100 1980 to 1980 35 0 7 DIN 200 to 600 328 to 1112 50 0 5 800 to 800 1440 to 1440 50 325 K DIN IEC 200 to 1350 328 to 2462 60 0 6 1550 to 1550 2758 to 2822 60 1 2 S DIN IEC 0 to 1750 32 to 3182 40 0 4 1750 to 1750 3118 to 3182 40 2 0 2 Accuracy of value accessed b
4. These can be used as an alert method that is activated with certain actions and trip levels FACTORY Contains preset parameters set by the factory These are not adjustable by the user only by the factory MULTIDROP This is where the Polling Address can be set This assigns a value for the device 0 15 within the HART network when there are several transmitters 13 TT421MAN 0109 The main information about the transmitter can be accessed here These include Tag Descriptor Message Date and Unique ID There is also a device info screen that contains additional important device information This includes Manufacturer Device Type Device Serial Number and software and hardware revision numbers among others TAG Eight character alphanumeric field for identification of the transmitter DESCRIPTOR 16 character alphanumeric field 8 CHARACTERS for additional identification of the transmitter May be used to identify service or location DESCRIPTOR DATE MODIFIED 16 CHARACTERS DATE MODIFIED The date may be used to MMDD YYA identify a relevant date as the last calibration the next calibration or the installation The date is SC CHARACTERS presented in the form of Month Day Year MESSAGE 32 character alphanumeric field for any other information such as the name of the person who made the last calibration some Fig 3 3 Terminal Information Tree special care to be taken etc UNIQUE ID Readable onl
5. joined at one end in what is called a measuring junction The measuring junction should be placed at the point of measure ment The other end of the thermocouple is open and connected to the temperature transmitter This point is called the reference junction or cold junction For most applications the Seebeck ef fect is sufficient to explain thermocouple behavior Smar Research Corporation 8 TT421MAN 0109 DAMPING SPAN DIGITALFILTER INPUT TRIM TYPE CONNECTION STANDARD SENSOR UNIT LINEARIZATION amp CJ TABLE COMPENSATION LRL URL MIN PV URV RANGING LRV BURNOUT TIME GENERATOR SP BUMPLESS A M ACTION 0 SP TRACKING ACTION 1 SP GENERAL SETPOINT i SP TABLE E ACTION Bar LIMIT 1 KP TR TD LIMIT 2 A M MV AUTO MANUAL N POWER ON ERROR SAFETY OUT HIGH i LIMITS LOW PID BLOCK OPTIONAL OUT MV FEEDBACK OP MODE PID OUTPUT CURRENT TRIM mA Fig 2 2 TT421 Software Function Block Diagram Omar Research Corporation 9 TT421MAN 0109 How the Thermocouple Works When there is a temperature difference along a metal wire a small electric potential unique to every alloy will occur This phenomenon is called Seebeck effect When two wires of dissimilar metals are joined on one end and left open on the other a tempera ture difference between the two ends will result in a voltage since the potentials generated by the dissimilar m
6. miter and the power supply Power Supply e Check output of power supply The voltage at the TT421 terminals must be between 12 and 45V and ripple less than 0 4V Electronic Circuit Failure e Locate the failure by alternately replacing the transmitter circuit and the interface with spare parts Transmitter Address e n On Line Multidrop item check if the address is O Symptom CURRENT OF 21 0 mA OR 3 6 mA Probable Source of Trouble Transmitter Connection e Check if the sensor is correctly connected to the TT421 terminal block e Check if the sensor signal is reaching the TT421 terminal block by measuring it with a multimeter at the transmitter end For mV and thermocouples test can be done with con nected and disconnected to the transmitter Sensor e Check the sensor operation it shall be within its characteristics e Check sensor type it should be the type and standard the TT421 has been configured to e Check if process is within the range of the sensor and the TT421 21 0 or 3 6mA current in XMTR mode indicates burnout Omar Research Corporation 23 TT421MAN 0109 Symptom INCORRECT OUTPUT Probable Source of Trouble Transmitter Connections e Check power supply voltage The voltage at the TT421 terminals must be between 12 and 45V and ripple less than 0 4V e Check for intermittent short circuits open circuits and grounding problems Noise Oscillation Adjust damping Check grounding of the tra
7. to apply the correct gain to the input signals to make them suit the A D converter A D Converter The A D converts the input signal to a digital format for the CPU Isolator Its function is to isolate the control and data signal between the input and the CPU CPU Central Processing Unit amp PROM The CPU is the intelligent portion of the transmitter being responsible for the management and operation of all other blocks linearization cold junction compensation and communication The program is stored in the PROM along with the linearization data for the temperature sensors For temporary storage of data the CPU has an internal RAM the data in the RAM is lost if the power is switched off however the CPU also has an internal nonvolatile EEPROM where data that must be retained is stored Examples of such data are calibration configuration and identification data D A Converter Converts the digital output data from the CPU to an analog signal Output Controls the current in the line feeding the transmitter It acts as a variable resistive load whose value depends on the voltage from the D A converter Modem Modulates a communication signal on the current line A 1 is represented by 1200 Hz and a O by 2200 Hz These signals are symmetric and do not affect the DC level of the 4 20 mA signal Power Supply Uses the power of the loop line to power the transmitters circuit This is limited to 3 9 mA Power Isolation Its funct
8. which action direct or reverse is configured in ACTION dPV MV Kp e edt Td dcc eras Auto Manual Optional The Auto Manual mode is toggled in INDIC In Manual MV may be adjusted by the user in the INDIC option The POWER ON option is used here to determine in which mode the controller should be on power up Limits Optional This block makes sure that the MV does not go beyond its minimum and maximum limits as estab lished by the HIGH LIMIT and LOW LIMIT It also makes sure that the Rate of Change does not exceed the value set in OUT CHG S These values are adjusted in the SAFETY LIMITS option Output Calculates the current proportional to the process variable or Manipulated variable to be transmit ted to the 4 20 mA output depending if the PID Module is ON or OFF This block also contains the constant current function configured in OUTPUT Current Trim The 4 mA TRIM and 20 mA TRIM are used to make the transmitter current comply with a current standard should a deviation arise Temperature Sensors The TT421 as previously explained accepts several types of sensors The TT421 is specially de signed for temperature measurement using thermocouples or thermoresistances RTDs Some basic concepts about these sensors are presented below Thermocouples Thermocouples are the most widely used sensors in industrial temperature measurements Thermocouples consist of two wires made from different metals or alloys
9. 3 of the input resis tance Ohms 0 2000 Ohms RTD IEC Pt500 Pt1000 0 03 of the input resistance TC Cold junction compensation rejection 60 1 Reference 25 0 0 3 C Power Supply Effect 0 005 of calibrated span per volt Vibration Effect Meets SAMA PMC 31 1 Electro Magnetic Interference Effect Designed to comply with IEC 801 Physical Specifications Electrical Connection Accommodates conductors up to 2 5mm 12 AWG Mounting Industry standard DIN Form B enclosure for easy integration Omar Research Corporation 26 TT421MAN 0109 CONTROL CHARACTERISTICS Optional PID Proportional Gain 0 to 100 Integral Time 0 01 to 999 min rep Derivative Time 0 to 999 s Direct Reverse Action Lower and Upper output limits 0 6 to 106 2596 Output rate of change limit 0 02 to 600 s Power on safety output 0 6 to 106 2596 Antireset windup Bumpless Auto Manual transfer Setpoint Generator up to 16 points up to 19999 minutes Alarm Dual trip levels adjustable over entire range High or Low action Acknowledge messaging 2 3 OR 4 WIRES DIFFERENTIAL SENSOR TYPE RANGE C MINIMUM C DIGITAL RANGE RANGE F MINIMUM C DIGITAL SPAN C ACCURACY SPAN C ACCURACY Cu10 GE 20 to 250 4 to 482 50 1 0 270 to 270 486 to 486 50 2 0 Ni 120 DIN 50 to 270 58 to 518 5 0
10. Held Terminal Should any problem be noticed related to the transmitter s output investigation may be carried out by the PALM as long as power is supplied and communication and the processing unit are operat ing normally The programmer should be connected to the transmitter in accordance with the wiring diagram shown on Section 1 Figures 1 4 1 5 and 1 8 Error Messages When communicating using the PALM the user will be informed about any problem found by the transmitters self diagnostics The messages are always alternated with the information on the top line The table below lists the error messages Refer to trouble shooting for more details on corrective action Diagnostics with the PALM DIAGNOSTIC MESSAGES PARITY ERROR POTENTIAL SOURCE OF PROBLEM Excessive noise or ripple OVERRUN ERROR Excessive noise or ripple CHECK SUM ERROR Excessive noise or ripple FRAMING ERROR Excessive noise or ripple NO RESPONSE LINE BUSY CMD NOT IMPLEMENTED TRANSMITTER BUSY The line resistance is not in accordance with load curve Transmitter not powered Interface not connected Transmitter configured in Multidrop mode being accessed by ON LINE SINGLE UNIT Other device using the line Software version not compatible between PALM and transmitter PALM is trying to carry out a TT421 specific command in a transmitter from another manufacturer Transmitter carrying out an imp
11. SmarResearch TechnologySource HART Fieldbus Profibus Intrinsic Safety Configuration Tools Semiconductors Training Custom Design Visit the SmarResearch technology center at www smarresearch com HART Intelligent Temperature Transmitter TT421 User Manual Features Smart two wire 4 20 mA loop power transmitter with HART communication Measures temperature using resistive sensors RTD s thermocouples sensors with resistance or mV outputs Linearization international standards and custom calibration according to Callendar Van Dusen Measurement Type Single sensor 2 3 or 4 wire configurations Dual Sensor Differential Average Maximum Minimum Extensive transmitter and sensor diagnostics Factory tested isolation for 1500V Mounts in industry standard DIN Form B connection head Configured to customer specifications prior to shipping 1 TT421MAN 0109 The 1 1421 is an intrinsically safe HART enabled intelligent temperature transmitter made by Smar Re search This device measures temperature using RTD s thermocouples resistance or mV input and out puts to an intrinsically safe 4 20mA current loop The TT421 is intended to mount in a industry standard DIN Form B connection head for easy integration with various sensors The TT421 meets all HART Foun dation physical layer requirements and is fully configurable through software The TT421 is in compliance with the following standards for equipment inte
12. aterials are different and do not cancel each other out Two important things must be noted First the voltage generated by the thermocouple is proportional to the difference between the measuring junction and the cold junction temperatures Therefore the temperature at the reference junction must be added to the temperature derived from the thermocouple output in order to find the temperature measured This is called cold junction compensation and is done automatically by the 1 1421 which has a temperature sensor at the sensor terminals for this purpose Secondly if the thermocouple wires are not used all the way to the terminals of the transmitter e g copper wire is used from sensor head or marshalling box new junctions with additional Seebeck effects will be created and ruin the measurement in most cases since the cold junction compensation will be done at the wrong point The relation between the measuring junction temperature and the generated millivoltage is tabulated in thermocouple calibration tables for standardized thermocouple types the reference temperature being 0 C Standardized thermocouple which are commercially used whose tables are stored in the memory of the TT421 are the following B E J N R S T v DIN L U Thermo Resistances RTDs Resistance Temperature Detectors most commonly known as RTD s are based on the principle that the resistance of a metal increases as its temperature increases S
13. d below RTD Resistive Temperature Detectors mV Linear Voltage Measurement Types Cu10 GE Types 6 22mV Ni120 DIN 10 100 mV Pt50 100 500 1000 IEC 20 500 mV Pt50 100 JIS Configurable for 2 wires or differential Configurable for 2 3 4 wires or differential Special Special Sensor is used for special Ohm Linear Resistance Measurement sensors e g load cells or resistive position Types 0 100 Ohm indicators It turns the TT421 into a 0 400 Ohm transmitter for mass volume position etc 0 2000 Ohm Types Ohm Resistive output Configurable for 2 3 4 wires or differential mV Voltage output Configurable for 2 3 4 wires or differential TC Thermocouples Types J R S T NBS Van Dusen L U DIN Types RTD s Configurable for 2 wires or differential Parameters RO A B C COLD JUNCTION This function is used to enable or disable the cold junction compensation for TC mV or special sensors This feature automatically compensates for temperature differences between the sensor location and the junction box location MEASUREMENT TYPE This parameter is used to set the measurement type for the selected sensor This effects the resulting primary variable value Only when using a sensor of type RTD Ohm TC or mV will a Measurement Type be selectable from the menu There are total of 5 measurement types Single Differential Average Maximum and Minimum Single is to be used when using a sin
14. e Pins 1 2 3 4 2 3 4 wire measurement circuit in accordance with EEx ia I for the connection of I S ther mocouples or RTD s Voltage U 65V DC Current lo 20mA Power Po 30mW Effective Internal Capacitance Cj s450nF Effective Internal Inductance Li negligible Maximum External Capacitance s550nF Maximum External Inductance Lo s20mH 9Smar Research Corporation 25 TT421MAN 0109 Loss of Input Burnout Failure Alarm In case of sensor burnout or circuit failure the self diagnostics drives the output to 3 6 or to 21 0 mA accord ing to the user s choice Humidity Limits 10 to 10096 RH Turn on Time Approximately 10 seconds Update Time Approximately 0 5 second Damping Adjustable 0 32 seconds Configuration This is done by an external Hand Held Terminal that communicates with the transmitter remote or locally us ing Hart Protocol Performance Specifications Accuracy See the following tables Ambient Temperature Effect For a 10 C variation mV 6 22 mV TC NBS R S T 0 03 of the input milivoltage or 0 002 mV whichever is greater mV 10 100 mV TC NBS E J N DIN L U 0 03 of the input milivoltage or 0 01 mV whichever is greater mV 50 500 mV 0 03 of the input milivoltage or 0 05 mV whichever is greater Ohms 0 100 Ohms RTD GE Cu10 0 03 of the input resistance Ohms 0 400 Ohms RTD DIN Ni 120 IEC Pt50 Pt100 JIS Pt50 Pt100 0 0
15. ferent value The function TRIM READING can be used to match the transmitter reading in Engineering Units to your plant standard thereby eliminating any eventual differences Unit The Engineering Units of the PALM display may be changed when the option PV UNIT of the RANGE function is selected The following units are available For mV input always mV For Ohm input always ohm For thermocouple and RTD input v degrees Celsius v degrees Fahrenheit Y degrees Rankine Y Kelvins Damping This RANGE function enables the electronic damping adjustment The damping may be adjusted between 0 and 32 sec Smar Research Corporation 19 TT421MAN 0109 TRIM The TRIM function is used to make the reading comply with the user s resistance voltage or current standards TRIM CURRENT READING EXIT 4 mA 20 mA EXIT ZERO GAIN FACTORY EXIT E y y CORRECT CORRECT ACTUAL ACTUAL Fig 3 6 Terminal Trim Tree ALARM The alarm function enables disables and configures the alarms The actions and trip levels can be configured independently for alarm 1 and 2 Alarm 0 is a non configurable alarm that indicates burnout When an enabled alarm condition is met an on screen alert wil
16. gle sensor For dual sensor applications all other measurement types may be used For dual sensor applications the sensors should be connected as described in Figure 1 5 Each Measurement Type is described below Single Used for all single sensor configurations Straightforward value from single sensor Differential Subtracts the sensor value from the sensor value See Fig 1 5 Average Calculates the average of the two sensor readings Maximum Sets the PV to the higher of the two sensor readings Minimum Sets the PV to the lower of the two sensor readings Smar Research Corporation 15 TT421MAN 0109 Special Sensor Configuration Special Sensor is a function that allows sensors whose characteristics are not stored in the TT421 memory as a standard to be used Any sensor may be used provided that the TT421 can accept the sensors output The mV and Ohm limitations can be seen in table 3 2 The sensors characteristic can be programmed into the TT421 s EEPROM in form of a 16 point table Such tables are usually made available by the sensor manufacturer but can also be obtained by testing it The special sensor function can not be used at the same time as the Setpoint generator To change the special sensor configuration select special in the sensor menu Special Types Ohm Resistive output mV Voltage output Configurable for 2 3 4 wires or differential LRL Lower Range Limit The minimum lower value that the
17. he output Low Limit Is the minimum allowable output in High Limit Is the maximum allowable output in SP TABLE Setpoint table When the Setpoint generator is on it will change the Setpoint automatically according to a table recipe To configure this table select SP TABLE in the menu AA Wi MONIT MONITORING This function allows simultaneous monitoring of 4 of the transmitters dynamic variables and output current on the display of the HPC301 Hand Held Terminal To activate it select MONIT in the main menu The display will show OUT Shows output in mA MV Shows output in 96 PV Shows Process Variable in the selected engineering unit TAmb Shows ambient temperature in deg C PV96 Shows Process Variable in 96 SP Shows Setpoint in 96 SP Shows Setpoint in the selected engineering unit TIME Shows the Setpoint generator time in min ER 6 Shows deviation between SP and PV Smar Research Corporation 17 TT421MAN 0109 This function determines the 4 20 mA output of the transmitter Here the transmitter can be re ranged or have the damping adjusted The Engineering Units displayed on the HPC301 Hand Held Terminal can also be changed Re Ranging The TT421 To re range a transmitter is to change the input values related to 4 mA and to 20 mA There are two ways to do it with the TT421 1 Using the HPC301 Hand Held Terminal from keyboard where signal input is not re
18. ion is to isolate the power supply between the input and the CPU Smar Research Corporation 6 TT421MAN 0109 TC Ohm RTD mV INPUT BOARD MAIN BOARD pe POWER SUPPLY ISOLATION SUPPLY lt C gt i PROCESSING UNIT PNE DIA ns gt POWER 7 EE aUD a RANGES SUPPLY L 2 L SPECIAL FUNCTIONS CAL Mux CONDI CONVER A PID OPTIONAL 2 TIONER TER T OUTPUT CONTROL N zu 0 SERIAL COMMUNICATION s MODEM A AN R HART PROTOCOL BELL 202 OUTPUT l 7 AMBIENT TEMPERATURE SENSOR Fig 2 1 TT421 Hardware Block Diagram Functional Description Software Refer to the block diagram Fig 2 2 The function of each block is described below Input Calculates the actual mV or Ohm value from the value sensed by the input circuitry Digital Filter This is a low pass filter with an adjustable time constant It is used to smooth noisy signals The Damping value is the time required for the output to reach 63 2 for a step input of 100 Input Trim Here the value obtained by READING TRIM is used to correct the transmitter for long term drift Standard Sensor Linearization amp Compensation Here the mV and Ohm measurements are linearized and cold junction compensated according to the sensor characteristics stored in the CPU The CPU contains data ab
19. l notify the user In addition alarm status may be monitored and acknowledged from alarm menu Acknowledge Acknowledges an alarm this will turn off alarm on the transmitter Alarm Configures the operation mode of the alarm off low or high Limits Configures the level at which the alarm will trip in Configuring Alarms Low The alarm is activated when PV is below the trip level decreasing signal High The alarm is activated when PV is above the trip level increasing signal Off The alarm is disabled 9Smar Research Corporation 20 TT421MAN 0109 ON LINE MULTIDROP OPERATION A multidrop connection is formed by several transmitters connected to a single communication trans mission line Communication between the host and the transmitters takes place digitally with the transmitters analog output deactivated XMTR mode or with the analog output activated PID mode The communication with the transmitters and the host PALM DCS Data Acquisition System or PC can be done with a Bell 202 Modem using Hart Protocol Each transmitter is identified by a unique address from 1 to 15 The TT421 is factory set to address 0 that means a non multidrop operation mode allowing trans mitter to communicate with the Hand Held Terminal superimposing the communication on the 4 20 mA signal To operate in multidrop mode the transmitter address must be changed to a number from 1 to 15 This change deactivates the 4 20 mA analog out
20. measurements sensors with cooling neck can be used or the sensor can be mounted sepa rated from the transmitter housing Use of sun shades or heat shields to protect the transmitter from exter nal heat sources should be considered if necessary Humidity is fatal to electronic circuits In areas subjected to high relative humidity the device should be in stalled within an isolated panel which will protect it from the elements The electronic circuit is protected by a humidity proof coating but frequent exposures to humidity may affect the protection provided Measurement error can be decreased by connecting the sensor as close to the transmitter as possible and using proper wires see Section ll Operation Smar Research Corporation 2 TT421MAN 0109 Mounting is fast and easy using the industry standard DIN Form B connection head This product is com patible with any standard DIN Form B head type connections as well as any 4 20 mA HART communica tion network Terminals for the intrinsically safe 4 20mA current loop and the intrinsically safe sensor circuit are arranged on the top side of the TT421 enclosure The T T421 is comprised of a plastic enclosure con taining the electronics embedded in a casting compound Electric Wiring Access the wiring block by unscrewing the DIN Form B head connection cover The connection descrip tions can be seen on the label as well as in the diagram below Connection 5 and 6 are used for connectio
21. n to the HART network These connections are non polarized and thus do not require special attention re garding polarity when connecting to the HART network Connections 1 through 4 are used for the sensor terminals See Figure 1 1 for more connection details A typical connection ofthe TT421 being used as a transmitter can be seen below in Fig 1 2 NOTE All cables used for connection of the TT421 to the sensor and HART network should be shielded to avoid noise Connection Description Sensor Terminals Sensor Terminals Sensor Terminals Sensor Terminals 4 20mA HART Comm non polarized 4 20 mA HART Comm non polarized SmarResoarc se Teennology Soure Power Supply 250 Ohms TT421 Transmitter os 2 6 HPC301 Hand Held Terminal Fig 1 2 Wiring Diagram of TT421 working as a transmitter SPECIAL CONDITIONS FOR SAFE USE To ensure safe use of the TT421 according to amp ll 2G EEx ia IIC T5 T6 The TT421 shall be installed in an enclosure with a degree of protection IP20 as a minimum In case of installation of the TT421 in an enclosure made of plastic material or light alloy the material of the enclosure shall comply with clause 7 3 1 or clause 8EN 50014 1997 respectively Internal wiring within the enclosure shall comply with clauses 6 4 11 and 7 6 e EN 50020 2002 The following ambient temperature range applies for
22. nded for use in potentially explosive atmospheres amp ll 2G EEx IIC T5 T6 EN50014 1997 A1 A2 General Requirements EN50020 2002 Intrinsic safety i EN50284 1999 Equipment Group II Category 1G It is the purpose of this document to explain the setup installation operation and maintenance of the 1 1421 as well as provide all accompanying technical specifications and data For the most up to date infor mation on this product and other Smar Research products visit our website www SmarResearch com Section Page 1 Mounting amp Electrical 2 2 Operation 6 3 Programming 12 4 Maintenance amp Troubleshooting 22 5 Technical Data amp Specifications 25 The overall accuracy of temperature and other measurements depends on several variables Although the transmitter has outstanding performance proper installation is essential in order to maximize its perfor mance Among the factors which may affect transmitter accuracy environmental conditions are the most difficult to control There are however ways of reducing the effects of temperature humidity and vibration Temperature fluctuation effects can be minimized by locating the transmitter in areas protected from ex treme environmental changes In hot environments the transmitter should be installed to avoid as much as possible direct exposure to the sun Installation close to lines and vessels subjected to high temperatures should also be avoided For temperature
23. nsmitters housing especially for mV and thermocouple input Check the terminal block for moisture Check that the shielding of the wires between sensor transmitter and transmitter panel is grounded only in one end Sensor e Check the sensor operation it shall be within its characteristics e Check sensor type it shall be the type and standard that the TT421 has been configured to Electronic Circuit Failure Check the integrity of circuit replacing it with a spare one Calibration e Check calibration of transmitter Omar Research Corporation 24 TT421MAN 0109 Section 5 Technical Data amp Specifications Functional Specifications Inputs Options see table Output Signal Two wire 4 20 mA with superimposed digital communication HART Protocol Version 5 1 Transmitter Poll Response mode Common 4 20 mA Power Supply 12 to 45 Vdc Load Limitation 12 17 20 30 40 45 Power Supply Volts Zero and Span Adjustment Noninteractive by HPC301 Hand Held Terminal Temperature Limits Operation 40 C lt Ta 75 C temperature class T5 40 C lt Ta 60 C temperature class T6 Storage 40 lt Ta lt 120 C 40 lt T lt 2509F Terminal Parameters Pins 5 6 non polarized supply and signal circuit for connection to an intrinsically safe 4 20mA current loop Voltage Ui 28VDC Current l 93mA Power P 700mW Effective Internal Capacitance C lt 2 2 nF Effective Internal Inductance Li negligibl
24. o the RTD resistance alone V2 V1 RTD R x I Rx I RTDx I 21 R Ld v2 RTD o3 V V1 4 R Fig 2 4 Three Wire Connection In a 4 wire connection terminals 2 and 3 are high impedance inputs Thus no current flows through those wires and no voltage drop is caused The resistance of the other two wires are not interesting since no measurement is done on them Hence the voltage V2 is directly proportional to the RTD resistance V2 RTD x 1 R 2 v2 RTD Y 3 R Fig 2 5 Four Wire Connection A differential connection is similar to the two wire connection and gives the same problem see Fig 2 6 Terminal 3 is a high impedance input Thus no current flows through and no voltage drop is caused However the resistance of the other two wires will be measured and do not cancel each other out in the temperature measurement since linearization will affect them differently 12 V2 py Rex RTD 1 E a 4 R RTD 2 Alarm The alarms are software alarms and have no external contacts available on the transmitter The alarms are acknowledged by using the HPC301 Hand Held Terminal which can also view and configure them individually Omar Research Corporation 11 TT421MAN 0109 Section 3 Programming This
25. ortant task COLD START Start up or Reset due to power supply failure OUTPUT FIXED Output in Constant Mode Transmitter in Multi drop mode OUTPUT SATURATED Primary variable out of calibrated Span Output current in 3 8 or 20 5 mA XMTR mode only SV OUT OF LIMITS Cold junction temperature sensor out of operating limits Cold junction temperature sensor damaged PV OUT OF LIMITS Smar Research Corporation Input signal out of operating limits Sensor damaged Transmitter with false configuration PV out of range limits see table 22 TT421MAN 0109 Troubleshooting the Transmitter Symptom NO LOOP CURRENT Probable Source of Trouble Transmitter Connections e Check wiring polarity and continuity e Check for shorts or ground loops Power Supply e Check power supply output The voltage at the TT421 terminals must be between 12 and 45 Vdc and the ripple less than 0 4V Electronic Circuit Failure e Check the main board for defect by replacing it with a spare one Symptom NO COMMUNICATION Probable Source of Trouble Terminal Connections e Check terminal interface connections e Check if the interface is connected to the points COMM and or in the line between the transmitter and the load resistor Transmitter Connections e Check if connections are as per wiring diagram e Check line resistance it must be equal to or greater than 250 Ohm between the trans
26. out most available stan dard sensors Special Sensor Here the mV and Ohm measurements may be linearized according to a customer specified lineari zation table stored in TABLE X Y Sensor TYPE and CONNECTION is specified as well In UNIT the desired engineering unit is configured This unit is used in all communications with the transmit ter The LRL URL and MINimum Span are used to limit the range that can be set so it is within the table and device accuracy limits Ranging This is used to set the process values corresponding to the output of 4 and 20 mA in transmitter mode or process variable 0 and 10096 in PID mode In transmitter mode the LOWER VALUE is the point corresponding to 4 mA and UPPER VALUE is the point corresponding to 20 mA In PID mode the LOWER VALUE corresponds to PV 096 and UPPER VALUE corresponds to PV 100 Time Generator Optional Counts the time to be used by the Setpoint generator function It may be paused by using PAUSE and reset to zero by using RESET Omar Research Corporation 7 TT421MAN 0109 Setpoint Optional In this block setpoint tracking may be activated in SP TRACKING The setpoint is adjusted in INDIC The setpoint may also be generated automatically by turning the SP GENERATOR ON When running the setpoint generator will ramp and dwell the setpoint according to a table that can be configured in SP TABLE PID Optional First the error is calculated as SP PV or PV SP depending on
27. put sending it to 4 mA XMTR mode or keeps the 4 20 mA operation when the transmitter is configured for PID operating mode Ca 2 Y Cj Cc ja I S min Im ax 122 Li Lc j l Ve S min V max When intrinsic safety is a reguirement special attention must be paid to the entity parameters al lowed to that area Where Ca La Allowable Capacitance and Inductance Ci Li Non protected internal Capacitance Inductance of transmitter j up to 15 Cc Lc Cable capacitance and Inductance Voc Barrier open circuit voltage Isc Barrier short circuit current Vmax Maximum allowable voltage to be applied to the instrument Maximum allowable current to be applied to the instrument j To operate in multidrop mode it is necessary to see which transmitters are connected on the same line This operation is called polling and it is done automatically as soon as ON LINE MULTIDROP option is executed Smar Research Corporation 21 TT421MAN 0109 General SMAR TT421 intelligent temperature transmitters are extensively tested and inspected before de livery to the end user Nevertheless during their design and development consideration was given to the possibility of repairs by the end user if necessary In general it is recommended that the end user do not try to repair printed circuit boards Instead he should have spare circuit boards which may be ordered from SMAR whenever necessary Diagnosis with Smar Hand
28. quired 2 Using the HPC301 Hand Held Terminal with an input signal or calibrator as reference to applied input In transmitter mode the Lower Value always corresponds to 4 mA and the Upper Value to 20 mA in PID mode the Lower Value corresponds to PV 0 and the Upper Value to PV 100 Re Ranging From Keyboard The TT421 may be adjusted to give 4 and 20 mA corresponding to given temperature values The TT421 has the expected input from several standard sensors output at different temperatures programmed in its memory Therefore the zero and span input does not have to be generated when the TT421 is re ranged thus there is no need to connect it to a calibrator for re ranging purposes Observe that both LOWER and UPPER VALUES are completely independent Adjustment of one does not affect the other Although the following rules must be observed a Both LOWER and UPPER VALUES should not be smaller than lower range or greater than high range b The span UPPER VALUE LOWER VALUE should be greater than the MINIMUM SPAN If you intend to reverse a signal i e to have the UPPER VALUE smaller than the LOWER VALUE proceed as follows Make the Lower Value as close to the Upper Value as possible or vice versa observing the minimum span allowed set the Upper Value to the desired setting and then set the Lower Value Example If the transmitter is ranged so that considering that the Minimum Span IEC Pt100 is LOWER VALUE 4 mA
29. re factory configured with no passwords To avoid operation by nonauthorized persons in some critical levels of the Programming Tree it is recommended to configure all passwords and configuration levels prior to operation See PASSWORD option in Maintenance section On Line Single Unit Configuration To configure the transmitter on line certify that it is correctly installed with a suitable power supply and the minimum 250 Q load required Omar Research Corporation 12 TT421MAN 0109 Terminal Programming Tree Sensor Multidrop Fig 3 2 Terminal Programming Tree INFO The main information about the transmitter can be accessed here These include Tag Descriptor Message Date and Unique ID CONF The burnout can be changed between High or Low here MAINT Loop tests device resets operation counters password level setting and ordering codes can all be accessed here SENSOR Here the TT421 input can be configured to the sensor type and connection type that is being used PID All control parameters may be adjusted and monitored here MONIT Allows the user to monitor 4 of the transmitters dynamic variables and output current Smar Research Corporation RANGE The output related parameters can be configured here Lower Value Upper Value Unit Damping TRIM The transmitter indication can be calibrated to an Ohm mV and or a current standard here ALARM Set any of the 3 alarms here
30. s a function of the sensor output is tabulated The sensor output is entered as the x value The desired reading is entered as y value with the limitations 19999 Y 419999 Note the following limitations for the x values CONN TYPE 2 30r 4 DIFFERENTIAL WIRE each input O to 2000 0 to 1000 20 to 500 10 to 250 Table 3 2 Special Sensor Input Range 9Smar Research Corporation 16 TT421MAN 0109 PID This function allows the adjustment of the PID parameters including the Setpoint toggling of the Auto Manual mode and the tuning parameters Here is a list of configurations which can be performed in the PID function PID Controller ON OFF Tuning Parameters This feature allows you to enter values into the Kp Tr and or Td fields PV and SP readouts E U check box switches readout between engineering unit and percentage Setpoint Tracking Enables or disables setpoint tracking Control Action Select between Direct or Reverse Control Mode Select between Automatic or Manual Configure MV Set the Manipulated Variable Configure SP Set the Setpoint SAFETY LIMITS Control Limits This option allows the toggling of the SP Power On mode between Automatic Manual and Last Mode This option also enables the adjustment of the following parameters of the controller Safety out Is the output after a power interruption or during a failure Out Chg s Is the maximum allowable rate of change of t
31. section of the TT421 User Manual will briefly explain the HPC301 user interface and its various commands For more in depth information on the HPC301 software please refer to the HPC301 User Manual The Hand Held Terminal The Smar HPC301 Hand Held Terminal is the human machine interface used to maximize the advances of digital technology The TT421 firmware allows the following configuration features to be accessed by the Palm software HPC301 The operations which take place between the HPC301 Hand Held Terminal and the transmitter do not in terrupt the measurement and do not disturb the output signal The HPC301 Hand Held Terminal can be Transmitter identification and specification data Remote re ranging Special sensor parameter adjustments Constant current adjustment between 3 6 and 21 mA for loop test Monitoring of process variable in Engineering Units and mA Controller monitoring for Setpoint Process Variable Manipu lated Variable and Auto Manual status Controller parameters adjustment Setpoint generator parameters adjustment Diagnosis and determining of faults in the processor or in the Figure 3 1 Smar s HPC301 transmitter Hand Held Terminal connected on the 4 20 mA line up to 2 km away from the transmitter Terminal Programming Tree The Programming tree is a tree shaped structure with a menu of all the available software re Sources as shown in Figure 3 2 WARNING All transmitters a
32. software will Unit Engineering Unit that should be associated with the measured variable If one of over 100 standard units is selected it will automatically get its HART protocol code This way all supervisory systems supporting HART can access the unit Should a special unit be be configured to read necessary select SPECIAL in the UNIT menu URL Upper Range Limit The maximum upper value that the software will be configured to read Table x y Linearization Table Table that relates the measured input to reading X sensed input in Ohm or mV Y z desired reading Min Minimum Span The minimum Span that should be configurable in reading value not sensed input VARIABLES inH2O InHg ftH O mmH2O mmHg psi bar mbar g cm Pa KPa Ton ATM t m l min Gal m m h gal s I s Ml d ft s ft d m3 d Gal h Gal d ft h m3 m bbl s bbl m bbl h bbl d gal h Gal s I h gal d EMPERATURE PC F R VOLUMETRIC FLOW VOLUME gal Gal m bush Yd ft In LEVEL t m in cm mm mw mewa dr MASS bam Ton b Shton LTon MASS FLOW 9 s g min g h kg s kg m kg h kg d Ton m Ton h Ton d Ib s Ib m Ib h Ib d Ton d DENSITY SGU g cm kg m g ml kg l g l TWARD BRIX Baum H Baum L API So w Solv Ball MISC Ohm Hz mA 96 pH us cPo SPECIAL characters TABLE 3 1 Available Special Sensor Unit Special Sensor Table This is where the desired reading a
33. tandardized RTDs whose tables are stored in the memory of the TT421 are the following Y JIS 1604 81 8150 amp Pt100 VIEC DIN JIS 1604 89 Pt50 Pt100 amp Pt500 VIEC Pt1000 VGE Cu 10 Y DIN Ni 120 For a correct measurement of RTD temperature it is necessary to eliminate the effect of the resis tance of the wires connecting the sensor to the measuring circuit In some industrial applications these wires may be hundreds of meters long This is particularly important at locations where the ambient temperature changes a lot The TT421 permits a 2 wire connection which may cause measuring errors depending on the length of connection wires and on the temperature to which they are exposed see Fig 2 3 In a 2 wire connection the voltage V2 is proportional to the RTD resistance plus the resistance of the wires V2 RTD 2 xI 2 1 R e cw d lt gt V2 RTD d 3 4 R Fig 2 3 WON Connection Omar Research Corporation TT421MAN 0109 In order to avoid the resistance effect of the connection wires it is recommended to use a 3 wire connection see Fig 2 4 or a 4 wire connection see Fig 2 5 In a 3 wire connection terminal 3 is a high impedance input Thus no current flows through that wire and no voltage drop is caused The voltage V2 V1 is independent of the wire resistances since they will be canceled out and is directly proportional t
34. the TT421 40 C lt Ta lt 75 C temperature class T5 or 40 C lt Ta lt 60 C temperature class T6 Smar Research Corporation 3 TT421MAN 0109 1 1421 Transmitter Smaritesearch Technology Sour uu lt Power Supply C 250 Ohms Zu lt HPC301 Hand Held Terminal Fig 1 3 Wiring Diagram for the TT421 Working as Controller Connection of the TT421 working as a controller Optional should be as indicated in Figure 1 3 Connection of the TT421 in multidrop configuration should be done as in Fig 1 6 Note that a maximum of 15 transmitters can be connected on the same line and that they should be connected in parallel When many transmitters are connected to the same line calculate the voltage drop through the 250 Ohm resistor and verify that the voltage of the power supply is enough Fig 1 4 ATTENTION For proper operation the HPC301 Hand Held Terminal requires a minimum load of 250 Ohm between it and the power supply The HPC301 Hand Held Terminal can be connected to the communication terminals of the transmitter or at any point of the signal line by using a HART interface with alligator clips IMPORTANT When operating with dual sensors both cannot be grounded A minimum of one sensor must NOT be grounded for proper operation of the TT421 Make sure that the transmitter is operating within the operating area as shown on the load diagram Fig 1 6 Communica
35. tion requires a minimum load of 250 Ohm 1650 1500 o 1000 lt O 500 250 12 17 20 30 40 45 Power Supply Volts Fig 1 4 Load Curve Smar Research Corporation 4 TT421MAN 0109 c Co A 2 Wire RTD or Ohm input A Co gt Thermocouple or Millivolt input Differential Min Max Average in either RTD or Ohm input 3 Wire RTD or Fig 1 5 Sensor Wiring 4 Wire RTD or Ohm input E Differential Min Max Average in either Thermocouple or Millivolt input 2 go 27 TT421 Transmitter 1 TT421 Transmitter 2 roh Smaraes pr en TT421 Transmitter 15 Held Terminal Fig 1 6 Wiring Diagram for the TT421 in Multidrop Configuration Smar Research Corporation 1 250 Ohms Supply TT421MAN 0109 The TT421 accepts signals from mV generators such as thermocouples or resistive sensors such as RTD s The only criteria for compatibility is the signal must be within the input range For mV the range is 50 to 500 mV and for resistance 0 2000 Ohm Functional Description Hardware Refer to the block diagram Fig 2 1 The function of each block is described below MUX Multiplexer The MUX multiplexes the sensor terminals to the signal conditioning section ensuring that the voltages are measured between the correct terminals Signal Conditioner Its function is
36. y communication using the HPC301 Hand Held Terminal The 4 20 mA is the digital accuracy 0 03 T Not applicable for the first 20 of the range up to 440 C NA Not applicable Smar Research Corporation 27 TT421MAN 0109 RANGE mV Special 50 to 500 MINIMUM SPAN mV 10 00 DIGITAL ACCURACY 0 02 or 50 uV SENSOR 6 to 22 0 02 or 2 uV mV 10 to 100 0 02 or 10 uV 50 to 500 0 02 or 50 uV 28 to 28 0 1 or 10 uV mV DIF 110 to 110 0 1 or 10 uV RANGE MINIMUM DIGITAL OHM SPAN mV ACCURACY SENSOR Special 0 to 2000 20 0 02 or 0 20 Ohm 0 to 100 1 0 02 or 0 01 Ohm OHM 0 to 400 4 0 02 or 0 04 Ohm 0 to 2000 20 0 02 or 0 20 Ohm OHM DIF 400 to 400 4 Omar Research Corporation 28 TT421MAN 0109 ORDERING CODE MODEL TT421 TEMPERATURE TRANSMITTER Connection Type Two wires Three wires Four wires 2 dual wires Sensor Type CU10 GE NI120 DIN PT50 IEC PT100 IEC PT500 IEC PT50 JIS PT100 JIS OHM 2K OHM 400 TC Type B NBS TC Type E NBS TC Type J NBS TC Type K NBS TC Type N NBS TC Type R NBS TC Type S NBS TC Type T NBS TC Type TIPO J DIN TC Type TIPO K DIN TC Type S DIN TC Type T DIN OHM 100 SPECIAL OHM mV 22 100 mV 500 mV SPECIAL MV PT1000 IEC
37. y information The burnout can be changed between High or Low here Burnout Burnout can occur when the sensor reading is out of range or open In these cases the transmitter can be set to output the maximum limit of 21 mA by setting the burnout to High or the minimum limit of 3 6 mA by setting the burnout to Low If the TT421 operates as a controller the safety out in PID should be used instead Loop tests device resets operation counters password level setting and ordering codes can all be accessed here Here is a description of features which can be performed in the MAINTENANCE function Device Reset Power ON OFF Loop Test The output can be set to any desired value between 3 6 and 21 mA regardless of input Operations Counter This feature allows you to view the number of changes done to the Zero Span Fixed Current Trim 4 amp 20mA Burnout Sensor Auto Manual and Multidrop Passwords Set passwords and access levels Ordering Code Contains the factory ordering code of the device Smar Research Corporation 14 TT421MAN 0109 Here the 1 1421 input can be configured to the sensor type and connection type that is being used The TT421 supports RTD s thermocouples resistance or mV inputs Below is a list of the sensor types supported The TT421 also supports 5 different measurement types for RTD Ohm TC or mV sensor types single differential average maximum and minimum These measurement types are define
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