TERPS-8000-Users Manual
Contents
1. Applied Pressure lt Applied gt CR First Point Done lt Yes No gt CR H Change Slope This command changes the slope of the output function of the transducer The relationship between the applied pressure and the output signal can be shown in graphic form new set point span using the H command Output reading new off set lt zero using the S command 0 Applied pressure Figure 4 1 Output to Applied Pressure Graph Notes If S remains at 0 the before value and the H value is changed the slope pivots around zero If H remains the same slope and the S value is changed the whole slope goes higher or lower by the S value EN English KO473 Issue 4 20 Reply Reply Reply M User Message Command Reply Command Reply Command Reply O Communication Settings where H and S Commands Proceed with caution when using these commands o Do not use both commands together o Use one command and then assess the result before continuing Command H PIN pressure lt none gt Command H lt slope gt lt setpoint gt CR Command H Slope lt slope gt CR Set At lt setpoint gt lt Units gt CR where the slope is a gradient and set point is the reading value entered for an applied pressure This command sets a user defined message of 16 characters stored in non volatile memory Only ASCII characters 32 to 128 are stored all othe2. lt unit number gt CR 17 K0473 Issue 4 EN English Command Reply Result Query U Interactive Current units are lt Units gt lt unit number gt CR CR 0 mbar lt CR gt 13 mH O lt CR gt 1 Pa lt CR gt 14 torr lt CR gt 2 kPa lt CR gt 15 atm lt CR gt 3 MPa lt CR gt 16 psi lt CR gt 4 hPa lt CR gt 17 Ib ft lt CR gt 5 bar lt CR gt 18 inHg lt CR gt 6 kg cm lt CR gt 19 inH2004 lt CR gt 7 kg m lt CR gt 20 ftH004 lt CR gt 8 mmHg lt CR gt 21 mbar lt CR gt 9 cmHg lt CR gt 22 inH7020 lt CR gt 10 mHg lt CR gt 23 ftH 020 lt CR gt 11 mmHO lt CR gt 24 mbar lt CR gt D cmH gt 0 lt CR gt Note mbar can be selected using code 0 21 or 24 Each of these nonvolatile commands changes the pressure units of the transmitted reading U Reply Units lt Units gt lt unit number gt CR EN English K0473 Issue 4 18 8 4 PIN Protected Set up Commands Reply Reply Reply Reply Reply Reply Reply Proceed as follows C User Calibration This command allows the user to perform a two point calibration on the output of the device The calibration routine requires two pressures to be applied within the operating extremes and in units of pressure measurement set in the transducer The software calculates an offset and gain correction to all subsequent readings Command Cor C Inter
3. Translate into French German Italian Spanish Portuguese Brazilian Simplified Chinese and Russian THIS HARDCOPY IS NOT TO BE USED AS CAMERA COPY Page 3 of 40 K0473 Issue 4 Page 4 of 40 K0473 Issue 4 GE Measurement amp Control Trench Etched Resonant Pressure Sensor 8000 Series User Manual K0473 2012 General Electric Company All rights reserved Safety Pressure Toxic Materials Maintenance Technical Advice EC Directives CE e The manufacturer has designed this sensor to be safe when operated using the procedures detailed in this Manual Do not use this sensor for any other purpose than that stated e This publication contains operating and safety instructions that must be followed to ensure safe operation and to main tain the sensor in a safe condition The safety instructions are either warnings or cautions issued to protect the user and the equipment from injury or damage e Use qualified personnel and good engineering practice for all procedures in this publication Do not apply pressure greater the maximum safe working pressure to the sensor There are no known toxic materials used in this sensor The sensor must be maintained using the manufacturer s procedures and these should be carried out by authorised service agents or the manufacturer s service departments For technical advice contact the manufacturer A qualified technician must have the necessary technical kn
4. lt Parity NIEO gt lt Character Length gt lt Stop Bits gt lt Software Handshaking Y N gt lt Number of Termination Characters gt CR 0 Baud Rate lt Baud Rate gt Parity lt Parity Ignore None Odd Even CR Data Bits lt Char Length gt CR Stop Bits lt Stop Bits gt CR Handshake lt Software Handshaking Yes No gt CR Term Chars lt Number of Termination Characters gt CR O Interactive Enter PIN gt Enter PIN 0 19200 bps CR 1 9600 bps CR 2 4800 bps CR 3 2400 bps CR 4 1200 bps CR 5 600 bps CR 6 300 bps CR Select Baud rate 0 6 gt enter selection Enter parity N one l gnore E lven O dd gt Enter parity Enter number of data bits 7 8 gt Enter number of data bits Enter number of stop bits 1 2 gt Enter number of stop bits EN English K0473 Issue 4 22 Result P Change PIN Command Command Where Reply Result Command Reply Command Reply S Set Offset Command Reply Software Handshaking Y N gt Enter Y or N Number of termination characters 1 CR 2 CRLF gt Enter number of termination characters Accept these values Y N gt Enter Y or N fVentered EEPROM updated CR fNentered Current settings unchanged CR These settings take effect after switching off then on the power supply for the transducer This command sets the PIN of the transducer which m
5. Query Reply Query Reply V Transducer Type and Settings Command Query Reply Query Reply This direct mode only command sets the internal analogue to digital converter used to measure the ambient temperature value in non volatile memory n a T lt Diode Calibration gt CR AT Diode Cal lt Diode Calibration gt CR This command sets the transducer type pressure range and serial number in non volatile memory Transducer data Type Serial Number Sensor Serial Number Style Pressure Unit Number Minimum Pressure Maximum Pressure n a V Direct mode only 5 character text string AA 1 2 format serial number is a 7 digit integer G for Gauge A for Absolute 0 to 24 see the U command real numbers in pressure units real numbers in pressure units lt Type gt lt Serial Number gt lt Sensor Serial Number gt lt Style gt lt Pressure Unit Number gt lt Minimum Pressure gt lt Maximum Pressure gt CR Vi Type Serial Number Sensor SN Style Minimum Pressure Maximum Pressure lt Type gt CR lt Serial Number gt CR lt Sensor Serial Number gt CR lt Style gt CR lt Minimum Pressure gt lt Pressure Units gt CR lt Maximum Pressure gt lt Pressure Units gt CR EN English K0473 Issue 4 26 W Write to EEPROM This command sets the non volatile memory as listed below Command Query Query Reply Add
6. units A 5 lt CRLF gt This command string sets the new PIN the units in which the pressure reading is transmitted and the interval between transmissions Note Acommand with the prefix causes a reply to change to text i e Command R Reply lt Pressure value gt lt pressure units gt EN English K0473 Issue 4 10 7 9 Error Message Command String Limitations A command string must not be more than thirty characters The transducer ignores all the commands in a string containing more than thirty characters Network Mode Syntax In this mode an address field must be added to the start of the general format as follows Address COMMON PLT P2 oe cesses ria Ppn where Address is the address of the transducer to send the command is the end of the address field command is the single letter instruction Pl to Pr are the required numeric values Example 3 1 R lt CR gt Get device address 1 to transmit pressure Error messages are generated from two sources a User commands In a command string the transducer accepts correct commands and rejects incorrect commands An incorrect command causes the transducer to send an error message related to the command Error Message Format The form of the error message ERROR nn where nn is a decimal number Defined error numbers are 01 Bad command 02 Bad PIN 08 Out of range value received 32 Command string too long b Tran
7. 500 bar Liquids and group Il gases compatible with Inconel 625 Ranges 501 to 700 bar Group ii liquids and group ii gases compatible with Inconel 625 Fluid classification in accordance with EC directive 67 548 EEC Statements in accordance with Pressure Equipment Directive 97 23 EC Ranges 0 to 3 5bar 7 bar maximum Ranges up to 7 bar 70 bar maximum Ranges gt 7 to 70 bar 200 bar maximum The TERPS sensor should be connected to stable power supply between 6 and 28 Vdc Low jitter version require a less than 10 mA during normal operation Low power versions require less than 3 5 mA during normal operation During power up the sensor draws more than current than above it is recommended that the power supply can supply a short term peak of at least 20 MA K0473 Issue 4 EN English 5 2 RS485 and RS232 Versions 6 Measuring TERPS 6 1 Frequency and diode version Measuring the Frequency Measuring the Diode Voltage Calculating Pressure The TERPS sensor should be connected to a stable power supply between 11 and 28 Vdc Current drawn is a nominal 16 mA peaking to 32 mA The frequency and diode version of the TERPS sensor requires the user to measure a frequency and a voltage to calculate pressure The TERPS sensor has a very high level of repeatability which needs to be matched by the measurement system The frequency of the TERPS die is output as a TTL square wave referenced to ground in the range
8. EN English Reply Response 8 2 Information Commands Reply Reply 8 3 General Set up Commands Command Z lt CR gt lt Frequency Hz gt lt Diode voltage mV gt CR In direct mode changes between automatic transmission mode see A command and transmission of the frequency and voltage In network mode sends the last complete measurement cycle of the transducer as frequency and voltage Query n a Transducer Identity This command gets the identity and set up data from the transducer Either formatting character can be used with this command Command I lt CR gt lt Unit type gt lt Serial Number gt lt Style gt lt Range Unit Number gt lt Minimum Pressure gt lt Maximum Pressure gt lt Calibration Date gt lt Software Version gt lt Transmission Interval gt lt Units sent Y N gt lt Measurement Speed gt lt Filter Factor gt lt Filter Step gt lt User Message gt lt Units number gt lt Pin set Y N gt lt User Zero Y N gt lt gt CR Command I lt CR gt or lt I lt CR gt Device Device type TERPS 1234 lt CR gt S N Transducer serial number lt CR gt Range Pressure range lt CR gt Address gt Transducer address lt CR gt lt CR gt Press any key to continue lt CR gt Query n a A Auto send Reading This command sets the interval between each transmission The interval can be to one decimal place i e 0 1 seconds Entering a negative number causes an erro
9. from the transducer using the valid address All devices on the network respond to the address 0 In the addressed mode a device obeys the commands 9 K0473 Issue 4 EN English 7 8 General Command Format Special Note Transducers are shipped with the following initial settings unless alternatives have been requested Units mbar PIN 000 not set Address Direct mode Long error messages Present Communications set 9600 8 N 1 Update rate 1 reading second Filter disabled User message none A sequence of single letter commands control the transducer Some commands require one or more numeric values to follow the command letter The correct number of parameters must be sent for this particular command A comma separates all command fields The transducer accepts upper case or lower case letters Single commands should be in the form Command PARA leali ian Pn Where Command is a single letter command P1 to Pn are the required numeric values in the form mmm ddd or m ddddE xx e g 123 456 or 1 23456E02 Example 1 Single Command A 3 lt CR gt selects the output update of one reading every 3 seconds alternative command a 3 lt CRLF gt Command Strings The transducer also recognises a string of commands each separated by a semicolon After receiving a valid terminator the transducer accepts the command string Example 2 Multiple Commands Command String P PIN new PIN U
10. ranges Note The g sensitivity will also create an error in a high vibration environment and the unit should be mounted accordingly TERPS 81Xx is not a harsh media isolated product There is negligible change in offset due to mounting position and vibration Because the pressure media comes directly into contact with the sensor chip care must be taken to ensure the pressure media does not damage the sensing chip When mounting the sensor seal the mating surfaces Failure to properly seal may affect performance or calibration accuracy Male threaded pressure connectors must not be sealed or constrained against the face at the base of the thread The forward cone or flat face should always be used as indicated below V x Depth versions should not be used at hyperbaric pressures above 20 bar approximately 200 m of water EN English K0473 Issue 4 3 TERPS media compatibility 3 1 TERPS 81XX 3 2 TERPS 80XX 4 Pressure containment 4 1 TERPS 81XX 4 2 TERPS 80XX 5 Applying power to TERPS 5 1 Frequency and diode versions 0 to 3 5 bar non condensing dry gases compatible with silicon silicon dioxide RTV adhesive stainless steel 316L and glass Ranges 0 to 200 bar Fluids compatible with Stainless Steel 316L and Hastelloy C276 Ranges 201 to 350 bar Liquids and group Il gases compatible with Stainless Steel 316L and Hastelloy C276 Ranges 351 to
11. value entered in response to a prompt normally happens with inactive commands Repeat command with valid values in response to each prompt 1019 Timed out Key not pressed in the specified time period usually 20 seconds normally happens with inactive commands Repeat command entering response in less than 20 seconds between each character and send carriage return within the specified time EN English K0473 Issue 4 28 29 K0473 Issue 4 EN English EN English K0473 Issue 4 30
12. 73 Issue 4 EN English 7 Using RS485 and RS232 versions 7 1 Serial Data Communications 7 2 Applications 7 3 RS485 Connections supply Output is compensated pressure in user specified units RS485 bi directional digital communication no handshaking user programmable baud rate between 300 and 9600 baud 8 bit data 1 stop bit Format ASCII text pressure reading including pressure units User programmable reading rate from one reading per second to one reading per 999999 seconds The TERPS may be used as a single transducer directly connected to a serial interface It can also be part of a network of devices using the programmed addressing facility Each device on the network is a slave with a master device controlling the communications The installed transducer is completely controlled by the serial interface The TERPS transducer contains its characteristic data in an integral E PROM Stand Alone RS485 Electrical connections RS485 B or RS485 ve supply OV supply RS485 A or RS485 Transducer body screen Notes Other connectors available refer to manufacturer For electrical connections refer to the sales data sheet T_T ve RS485 OV address 00 pressure Figure 2 RS485 Direct connections EN English K0473 Issue 4 A RS485 interface B RS485 B en device 1 device 2 IBM PC or compatible device address 1 u address 2 t ft Figure 3 RS485 Network conne
13. GE Druck Pressure measurement for research amp industry Druck Limited Fir Tree Lane Groby Leicester LE6 OFH England Tel 0116 231 7100 Trench Etched Resonant Pressure Sensor TERPS 8000 Series User Manual K0473 Druck Limited 2012 This document is the property of Druck Limited and may not either in part or whole be copied or otherwise reproduced communicated in any way to third parties nor stored in any data processing system without the express written authority of Druck Limited Page 1 of 40 K0473 Issue 4 Amendment Record Iss C N ii Workflow No Date No Originator Typed No Amendments 1 20 12 10 N A Robert Lee Robert Lee 156219 New document Delete two 80xx pressure ranges 2 24 06 11 26758 Robert Lee Robert Lee 165022 change power supply voltage from 5 to 6 Vdc Change pascal to hecto pascal 27245 Glenn Glenn 0 2mV C to 2m V C Equations 3 SOLA 27300 Roles Roles MARTE changed on page 5 Pressure range changed on page 4 25 to 40khz 4 30 01 12 27572 RobertLee RobertLee 176971 Page 11 7 90 add 5 of span after An applied pressure Approvals Engineering M COLE Marketing I ABBOTT Page 2 of 40 Electrical R CRADDOCK Technical Communications R LEE K0473 Issue 4 Print Instructions Finished Size A5 Print in colour on white throughout covers text saddle stitched e Cover to 285 gsm content to 100 gsm
14. Reply The following command codes can only be accessed using a factory PIN These command codes can be queried by the user The transducer sends the data settings stored in non volatile memory for the queried commands code This direct mode only command sets the measured frequency of the crystal oscillator in non volatile memory n a E lt Reference Frequency gt CR E Reference Frequency lt Reference Frequency gt kHz CR This direct mode only command sets the calibration coefficients in non volatile memory n a L lt Coefficient0 0 gt lt Coefficient 0 1 gt lt Coefficient0 2 gt lt Coefficient 0 3 gt lt Coefficient 0 4 gt lt Coefficient 1 0 gt lt Coefficient 5 3 gt lt Coefficient 5 4 gt lt Frequency Offset gt lt Diode Offset gt lt Calibration Date gt CR K 0 0 lt Coefficient 0 0 gt K 0 1 lt Coefficient 0 1 gt K 0 2 lt Coefficient 0 2 gt CR K 0 3 lt Coefficient 0 3 gt K O 4 lt Coefficient 0 4 gt CR K 1 0 lt Coefficient 1 0 gt K 5 4 lt Coefficient 5 4 gt CR CR Frequency Offset X lt Frequency Offset gt Diode Offset Y lt Diode Offset gt CR Serial Number lt Serial Number gt Calibration Date lt Calibration Date gt CR Curve Fit lt X order gt x lt Y order gt CR CR Type lt CR gt to continue CR Waits 20 seconds or for CR 25 K0473 Issue 4 EN English T Analogue Digital Converter Set up Command
15. active Enter PIN gt enter PIN Apply first pressure then send lt CR gt when stable send lt CR gt Enter applied pressure lt units gt gt enter pressure value in specified units lt CR gt Apply second pressure then send lt CR gt when stable send lt CR gt Enter applied pressure lt units gt gt enter pressure value in specified units lt CR gt Pressure gain lt new pressure gain gt CR Pressure offset lt new pressure offset gt CR Accept these values Y N gt Enter Y or N Y answered EEPROM updated lt CR gt N answered Current settings left unchanged lt CR gt If invalid data entered 1022 bad cal pres lt CR gt Command C PIN mode lt CR gt Non interactive calibration requires the C command to be used twice i e two calibration pressures must be entered for a straight line fit Command C PIN 1 2 lt CR gt where PIN is the PIN of the transducer and 1 is the first pressure value Apply pressure 1 when stable send C PIN 1 lt CR gt Note Sending C PIN 1 lt CR gt causes the current stored data for pressure 1 to be sent Apply pressure 2 when stable send C PIN 2 lt CR gt 19 K0473 Issue 4 EN English Query C PIN mode Reply lt Measured gt lt Applied gt lt Got first point Yes No gt CR Query C Reply Measured Pressure lt Measured gt CR
16. ctions device 3 address 3 7 4 RS232 Stand Alone RS232 Electrical connections Connections Tx ve supply OV supply Rx Data ground GRD connects to OV supply ITA OV ve address 00 lt _ pressure GRD Rx Tx TL RS232 Figure 4 RS232 Direct connections K0473 Issue 4 EN English 7 5 Command The following functions can be performed using the serial data link Summary FUNCTION COMMAND Measurement Transmit pressure reading seen Trigger new reading and transmit a RegdTaW datdi cino licei Information Identity and set up information s1101101121121 General set up Set automatic transmission interval A Setifilten iotiucioznile lola lane dia F Set device address eme rene N Pressure measurement speed Q Set output pressure UNIS sierici U PIN Set up Digital output calibration Set full scale ee ce H User MESSAGE eein aae i A M Communication settings in O Change PN nnana n P Setoffset vsciioi anna S Command Terminators a scri pai lt CR gt OO RAI E lt CRLF gt ead Tid se e lt gt Note Waiting 20 seconds after entering a valid command has the same effect as lt CR gt The backspace character deletes typing errors before a command character causes a text reply EN English KO473 Issue 4 8 FUNCTION QUERY General set up Filter setting f Device address N Pressure measurement speed 0 Output pressure Units see
17. eadings are filtered using a factor of the sum of the two values The Filter Step takes a value expressed as an integer percentage of full scale If step 0 then the filter is disabled If the percentage change between last pressure reading and the current pressure reading exceeds the filter step value the current reading passes through unfiltered lt None gt A filtered value within the filter step band this change is nonvolatile 15 K0473 Issue 4 EN English Reply Reply Reply Reply Result Reply Result Example Reply Reply Query F lt Filter Factor gt lt Filter Step gt Query F Filter Factor lt Filter Factor gt Filter Step lt Filter Step gt N Set Device transducer Address This command sets the address of the transducer A valid address is a number between 0 and 32 Setting the address to zero causes the transducer to go into direct mode All other address settings cause the transducer to go into network mode This command has a secondary function and uses N 0 or N 0 to change the length of error messages where 0 direct mode Command N new address none Command N 0 none Changes to short error messages where 0 direct mode Command N 0 none Changes to long error messages where 0 direct mode Address 1 change to long error messages 1 N 1 Query N lt Device Address gt CR Query N Device Address lt Device Address
18. es a 2 d order pressure P and a zrd order temperature signal T If other orders of fit are used these equations will need to be expanded to suit This equation is in the form 3 i T Re x y y P 2 i 0 j 0 Where P Applied pressure psi Kj Calibration coefficient x Pressure signal in Hz minus normalising factor X y Temperature signal in mV minus normalising factor Y So P Kyy x y Ko 0 9 Kop a y Koy y KK x y Ky ext y ET y Kay lt x 9 Koy 2 ET x Kyq x The x variable is the pressure sensitive measured output from the sensor in Hz minus the normalising factor X The y variable is the temperature sensitive measured output from the sensor in mV minus the normalising factor Y The coefficients Kij X and Y are printed on the top right hand corner of the calibration certificate supplied with the pressure sensor A sample set is shown below COEFFICIENTS KOO 1 3637058e 003 KO1 1 7893979e 002 K10 5 1512798e 001 K11 5 1314069e 007 K20 9 8964506e 006 K21 1 8445312e 010 K30 7 3191807e 011 K31 2 4814713e 013 K02 1 1991925e 003 K03 3 6348882e 006 K12 1 0023045e 009 K13 3 1389001e O11 K22 3 0921206e 014 K23 5 4223801e 015 K32 1 6169537e 015 K33 3 2931808e 017 X 2 9248364e 004 Y 5 5272950e 002 SN 41 CS 4 2793627e 030 SN refers to the serial number of the unit CS is a check sum of the data and can be ignored K04
19. gt CR Q Set Measurement Speed This command changes the rate of measuring by changing the number of output cycles counted for each reading The RPT EN English K0473 Issue 4 16 Command Reply Query Reply Reply U Set Units Command Where Reply Result Query Reply produces an output at 16000 cycles per second and by selecting one of 6 settings 0 to 5 a sample rate can be made The highest rate 5 causes the most electrical noise Note Increasing the Q speed may for the next two seconds cause reading errors or 020 No Frequency error message to be returned Q speed setting none Q lt Measurement Speed gt CR Query Q Measurement Speed lt Measurement Speed gt CR Q Resonant Measurement Interval G Command Sensor milliseconds 2 Command Setting Cycles minimum maximum fixed setting Counted 0 64000 1400 2100 4 0 1 32000 710 1050 2 0 2 1 16000 360 530 1 0 3 8000 180 260 0 50 4 4000 90 130 0 25 5 2000 50 75 0 25 1 Default setting for the accuracy stated in the specification 2 This interval varies between minimum and maximum This command sets the units of pressure measurement Either formatting character can be used with this command U nn lt CR gt nn is a number between 0 and 24 used to select the required units lt none gt Changes the pressure units of the transmitted reading U
20. ii Abbreviations continued Pa Pascal pc Personal computer PIN Personal identification number ppm Parts per million psi Pound per square inch RS232 Serial data communication standard RS485 Serial data communication standard TERPS Trench etched resonant pressure sensor V Volt VA Volt amp SC Degrees centigrade iii K0473 Issue 4 EN English EN English K0473 Issue 4 iv 1 Introduction 1 1 General The 8000 Series uses TERPS trench etched resonant sensor technology The RPS 8000 produces a frequency and diode voltage output The DPS 8000 includes a microprocessor to produce a serial digital output Figure 1 TERPS General view 1 2 Configuration The following variables are specified at the time of ordering a Pressure range b Pressure connector E Cable length d Option A Increased accuracy e Accessories i User Manual this publication ii Calibration certificate 1 K0473 Issue 4 EN English 2 Installation 2 1 Connecting TERPS to a pressure source TERPS 80XX is a harsh media isolated product Isolation is achieved by hermetically sealing the sensor chip in an oil filled chamber The weight of this oil gives a g sensitivity as a pressure offset error To calibrate the TERPS 80XX the unit is mounted vertically with the pressure port at the lowest point Orientation other than this produces a pressure offset error as specified in the datasheet The error is most noticeable at lower pressure
21. long wrong type etc Check command string sent 1008 Bad Format Invalid formatting character sent in command string or command is interactive Check command string sent requires a valid formatting character 1009 Miss g Param At least one of the required parameters missing from command string Check command string sent 1010 Invalid PIN Incorrect PIN for the command sent Check command string sent 1011 Bad value Out of range value sent to the transducer Send in range value 1012 Bad BUS Cmd Command sent to transducer in Network mode Send this command with transducer in Direct made 1013 Cal Error Corrupt calibration data detected transducer pressure measurement unreliable Return to GE Sensing for recalibration 1014 Press Range Corrupt calibration data detected pressure range not known transducer pressure measurement unreliable Return to GE Sensing for recalibration 1015 Under Press Pressure applied below calibrated limit Check for system fault where transducer is installed 1016 over Press Pressure applied above calibrated limit Check for system fault where transducer is installed 1017 Bad global Command sent to the transducer as a global 0 command not valid as a global command in network mode Send the command to each transducer in turn using correct address in place of global 0 1018 Bad response Invalid
22. n U PIN Set up Digital output calibration 125110112012 C Full scale value H User message M Communication settings 0 PIN SET roan er P OMSELValMe a iaia S Factory Set up Query only Crystal Reference Frequency ae E Load Calibration CoefficientS L Analogue Digital Convertor Set up coh Transducer Type and Settings V Write to EEPROM he dns W 7 6 Measuring The frequency output from the sensor is counted for a fixed number Pressure of cycles by the microprocessor At atmospheric pressure this takes a nominal 400 milliseconds The output from the integral temperature sensing diode takes 400 milliseconds for a single conversion through the discrete converter Measurement cycles are continuous each cycle delivers new values of frequency and temperature 7 7 Communication The TERPS smart transducer operates in one of two operating Modes modes direct and addressed These modes are controlled by sending the transducer an address number Direct mode The valid address in direct mode is zero In this mode the transducer continuously transmits data at an interval set by the user Before any command can be sent to the transducer the data stream must be stopped by sending another single byte character or back space The full set of commands are then available Addressed mode The valid address in addressed mode is a number between 1 and 32 In this mode data has to be polled
23. of 25 to 40 kHz The frequency of the square wave needs to be measured to a better than 6 5 digits i e 30 KHz to better than 0 05 Hz to allow the sensor to meet quoted specification To make sure the calculated output is correct the measurement device should be regularly calibrated in accordance with manufacturer s instructions against a traceable standard The diode signal is referenced to ground It is a nominal 0 5 V at room temperature and changes with a nominal 2mV C To achieve the quoted specification of the sensor this signal must be measured to better than 0 01mV To make sure the calculated output is correct the measurement device should be regularly calibrated in accordance with manufacturer s instructions against a traceable standard Note Best practice when measuring a TERPS device is to take both measurements synchronously Where this is not possible the measurements should be taken as closely together as possible Control the environment in which the TERPS is situated so it is not subjected to sudden changes in temperature and pressure During manufacture a large number of pressures and temperatures are applied to the sensor to build up a mathematical description of its behaviour This data is then used to generate a polynomial equation that relates the measured outputs from the sensor bridge output and temperature output to the applied pressure EN English K0473 Issue 4 The following example assum
24. owledge documentation special test equipment and tools to carry out the required work on this equipment This equipment complies with BS EN 61000 6 1 2007 BS EN 61000 6 2 2005 BS EN 61000 6 3 2007 BS EN 61000 6 4 2007 BS EN 61326 1 2006 This equipment complies with the requirement of the Pressure Equipment Directive 97 23 EEC For further details see the Sales Data Sheet A full conformity certificate is available from the manufacturer Contact GE Measurement amp Control www ge mcs com K0473 Issue 4 EN English Abbreviations The following abbreviations are used in this manual Note Abbreviations are the same in the singular and plural a ASCII atm bps cmHg CR DC EEPROM FS ftH 0 hPa inHg inH20 kg kg cm kg m kPa Ib ft LF mA mbar mbar a mHg mH 0 mm mmHg mmH 0 MW MPa n a Absolute American Standard Code for Information Interchange Atmosphere Bits per second Centimetre of mercury Carriage return Direct current Electrically Erasable Programmable Read Only Memory Full scale Feet of water hecto Pascal Inch of mercury Inches of water Kilogram Kilogram per centimetre squared Kilogram per metre squared Kilo Pascal Pounds per foot squared Line feed Milli Ampere Millibar Millibar absolute Metre of mercury Metres of water Millimetre Millimetre of mercury Millimetres of water Mega ohm Megapascal Not applicable EN English K0473 Issue 4
25. r Note Setting this interval to less than the measurement interval Q Command causes the output of the same reading twice or more EN English K0473 Issue 4 14 Where Reply Result Where Reply Result Reply Reply Where Reply Result Command A nnnnnn lt CR gt nnnnnn is a number between 0 and 999999 This is the interval in seconds between successive transmissions None in network mode In direct mode lt Pressure reading gt CR lt Pressure reading gt CR A reading is transmitted every nnnnnn seconds in the format set in the set up commands The interval input is nonvolatile Command A nnnnnn lt CR gt nnnnnn is a number between 0 and 999999 This is the interval in seconds between successive transmissions None in network mode In direct mode lt Pressure reading gt lt Units gt CR lt Pressure reading gt lt Units gt CR A reading is transmitted every nnnnnn seconds The interval input is nonvolatile Query A lt Transmission interval set gt lt Y if Units displayed N if units not displayed gt CR Query A Interval lt Transmission interval set gt CR Units lt Yes if Units displayed No if units not displayed gt CR F Change Filter Settings This command sets the filter applied to the pressure reading R Command network mode or direct mode pressure reading Command F Filter factor Filter step The last two pressure r
26. ress Meaning 1 Wipe the first bank of the EEPROM 2 Wipe the second bank of the EEPROM 3 Wipe the both banks of the EEPROM 4 Wipe the calibration coefficients in both banks 5 Copy from bank 2 to bank 1 6 Copy from bank 1 to bank 2 n a W Reply lt Byte 0 gt lt Byte 1 gt lt Byte 2 gt lt Byte 3 gt lt Byte 4 gt lt Byte5 gt lt Byte 6 gt lt Byte 510 gt lt Byte 511 gt CR W 000 gt lt Byte 0 gt lt Byte 1 gt lt Byte 15 gt CR 010 gt lt Byte 16 gt lt Byte 17 gt lt Byte 31 gt CR OFO gt lt Byte 240 gt lt Byte 241 lt Byte 255 gt CR CR Send lt CR gt to continue CR Waits 20 seconds or for CR 100 gt lt Byte 256 gt lt Byte 257 gt Byte 271 gt CR 1F0 gt lt Byte 496 gt lt Byte 497 gt lt Byte 511 gt CR Send lt CR gt to continue CR Waits 20 seconds or for CR 27 K0473 Issue 4 EN English Table 1 Fault Finding Error Message Probable cause Action 1002 EEPROM error Failure of non volatile memory Return to GE Sensing for repair or replacement 1004 Bad command Command character not recognised Check command string sent Check the serial interface connection 1005 Bad char Illegal character sent in a command string Chec Chec command string sent is valid the serial interface connection 1006 Bad Paramis Invalid parameters sent in command string out of range too
27. rs will be removed from the final string ASCII 0 indicates the end of message and stores this in memory but does not transmit this character The CR character is transmitted with the message but not stored in memory Attempting to store the colon character causes an error 022 Bad Message M PIN message M PIN message lt none gt M lt message gt CR M Message lt message gt CR This command sets the communications for the transducer The settings can be either interactive or non interactive Baud rate number between 0 and 6 or an actual rate Parity set with a single letter ignore N None O Odd E Even Character length 70r8 Stop bits lor2 21 K0473 Issue 4 EN English Command where Reply Command where Reply Command Reply Command Reply Command Reply Software handshaking Y or N Yes or No Termination characters 1 or 2 1 transmitted lines must end in CR received lines end in either CR or LF 2 transmitted lines must end in CRLF received lines end in CRCR or CRLF or LFLF or LFCR O PIN n lt CR gt O PIN Baud Rate Parity Character Length Stop Bits Software Handshaking Number of Termination Characters lt none gt O PIN n lt CR gt O PIN Baud Rate Parity Character Length Stop Bits Software Handshaking Number of Termination Characters lt none gt 0 lt Baud Rate
28. rts a new measurement cycle and when completed transmits the reading Command G lt CR gt lt Pressure reading gt CR Transmission of the reading takes 1 5 times the current measurement interval set by the Q command Command G lt CR gt Reply lt Pressure reading gt lt Units gt CR EN English K0473 Issue 4 12 Result Reply Result Reply Result Reply Transmission of the reading takes 1 5 times the current measurement interval set by the Q command Global Command 0 G lt CR gt lt Address gt lt Pressure reading gt CR All devices on the network are triggered to transmit a reading After atime interval set by the Q command and a further time interval set by the O command each device on the network transmits a reading Global Command G lt CR gt lt Address gt lt Pressure reading gt lt Units gt CR All devices on the network are triggered to transmit a reading After atime interval set by the Q command and a further time interval set by the O command each device on the network transmits a reading and the selected units Query n a Z Read Raw Data This command sends the last complete measurement cycle of the transducer as frequency and voltage Note The frequency value is proportional to the applied pressure and the voltage is proportional to the temperature sensed by the diode Command Z lt CR gt lt Frequency gt lt Diode voltage gt CR K0473 Issue 4
29. sducer fault A transducer fault sends an error message blocking the transmission of pressure data and sending the fault message in place of data Error messages An applied pressure 5 of span out of the calibrated range causes Over Pressure Under Pressure A damaged transducer or no frequency output from the transducer causes KKK NO RPT KKKK 11 K0473 Issue 4 EN English 8 Command Definitions 8 1 Measurement Commands Reply Result Reply Result Reply Result The commands have been defined for direct mode operation address 0 In the addressed mode an address field will be added to the start of the command and reply For example Get reading command Command direct R lt CR gt addressed Address R lt CR gt Address R lt CR gt Reply direct Pressure value pressure units lt CR gt addressed Address Pressure value pressure units lt CR gt Address lt Pressure reading gt lt units gt lt CR gt R Get Reading This command polls the devices in the network for a reading Although used mainly in the addressed mode it can also be used in direct mode Command R lt CR gt Pressure value pressure units lt CR gt A new pressure reading is transmitted Command R lt CR gt lt Pressure value gt lt pressure units gt lt CR gt Anew pressure reading and the units of pressure measurement are transmitted Query n a G Get New Reading and Transmit This command sta
30. ust be used to access the PIN protected settings To change this setting the current PIN must be used and can be integers between 0 and 999 P current PIN new PIN Where PIN is the PIN of the transducer NewPIN is the replacement PIN Reply lt none gt Result The PIN of the transducer changes to new PIN P current PIN new PIN current PIN is the PIN of the transducer new PIN is the replacement PIN lt none gt The PIN of the transducer changes to new PIN P Y if PIN set N if PIN not set CR P Pin Set Yes if PIN set No if PIN not set CR This command adds an offset value to the output of the transducer S PIN pressure lt none gt 23 K0473 Issue 4 EN English Result Command Reply Command Reply The transducer stores the value set with the Scommand in non volatile memory S lt Offset gt lt Setpoint gt CR 5 2 Offset lt Offset gt lt Units gt CR Set at lt Setpoint gt lt Units gt CR The transducer stores the value entered as lt Setpoint gt The H command also uses this set point value To remove the set point send S PIN X This sets the stored set point value to zero EN English K0473 Issue 4 24 8 5 Factory Set Commands Query Only E Crystal Reference Frequency Command Query Reply Query Reply L Load Calibration Coefficients Command Query Reply
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