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Part 2: Communication commands Operating instructions

1. Example 024 Hardware and parameter error After RES power up or error status readout the contents of the register are cleared HBM Operation with processor or terminal 68 PW20i Communication commands 3 7 Commands for Legal for trade applications LFT Legal for Trade ae Legal for trade applications Range 0 1 Factory setting O off Response time lt 50 msec Parameter 1 Password protection no Parameter backup with input Query LFT Effect 0 1 crif Command LFT0 1 Effect 0 mandatory calibration switched off 1 mandatory calibration switched on Each time the LFT command is changed the standard meter TCR is increased by 1 With LFT1 application subject to mandatory calibration the standard meter is increased by one for each parameter input of the following commands CRC DPW IDN LDW LWT LIC NOV ZSE ZTR This means that every change to these calibration relevant parameters can be detected by the standard meter TCR which cannot be reset HBM Operation with processor or terminal PW20i Communication commands TCR HBM 69 Trade Counter Legal for trade counter Range no input possible Response time lt 10 msec Parameter none Password protection no Parameter backup not required Query Effect TCR xxxxxxxx Crif 8 characters crlf This counter cannot be reset and it marks the parameter changes of the commands relevant to calibration s
2. lt 10 msec 5 no with TDD1 The PW20i contains 2 limit value switches with selectable hysteresis These can monitor gross or net measured values The limit values are set internally and can be queried in the measurement status MSV COF or with the POR command P4 should normally be larger than P5 The limit value switch will in this case switch to ON when the measured value exceeds the P4 value and reset when P5 is undershot see Notes Input LIV P1 lt P2 P3 P4 P5 gt P1 p2 P3 P4 Number of the limit value switch 1 or 2 Limit value monitoring on off O off 1 a limit value bit is set in the measurement status Input signal of limit value switch 0 1 0 Net measured value 1 Gross measured value 2 MAV value see trigger function Activation level When the measured value exceeds P4 the limit value bit in the measurement status is set 1 P4 0 NOV Activation level with NOV gt 0 P4 0 1599999 Activation level with NOV 0 Operation with processor or terminal PW20i Communication commands P5 57 Deactivation level When the measured value undershoots P5 the limit value bit in the measurement status is reset 0 P5 0 NOV Activation level with NOV gt 0 P5 0 1599999 Activation level with NOV 0 The measurement status is output with the measured value in certain formats see COF Example Query Effect Query Effect Notes ee Ra y we e N HBM LIV 1 1 0 120000 11000
3. selectable via ICR sampling rate lt 600 Hz The required filter effect and output rate can be set using the commands ASF ICR and FMD In addition to the standard filter properties additional new more powerful digital filters have been implemented The command FMD is used to toggle between the two filter methods FMD 0 Standard filter FMD 1 Fast settling filter Operation with processor or terminal PW20i Communication commands 39 HBM Filter characteristics of standard filter FMDO Settling time Limit frequency Hz Max attenuation dB in ms to 1 o at 3dB at 300 Hz 22 53 INIA BR WO PM With ASFO the filter is deactivated The limit frequency of the filter determines the settling time The higher the filter index the better the filter effect but the longer the settling time when changing the weight The filter setting should be chosen to be as low as possible while still being able to ensure non operation standstill at a weight that does not change The FIR filters FMD1 can be described with the following table Settling Limit 20 dB 40 dB Attenuation Stop band time in ms frequency attenuation at attenuation at in stop Hz at 3 dB Frequency Frequency band dB Hz Hz Hz 1 62 18 47 63 gt 90 gt 90 2 90 11 32 45 gt 90 gt 70 3 119 9 24 31 gt 90 gt 60 4 147 7 18 24 gt 90 gt 60 5 208 5 12 17 gt 90 gt 4
4. 01 2 paaa naaa naaa eee NG 4471 Terminator Execution TEX 207 Trade Counter TCR aaa 69 Operation with processor or terminal 79 Transmit Device Data TDD 63 Trigger Command TRC aaa 53 Z Zero Setting ZSE aa 491 Zero tracking ZTR aa 487 HBM A1561 1 0 en Modifications reserved All details describe our products in general form only They are not to be understood as express warranty and do not constitute any liability whatsoever Hottinger Baldwin Messtechnik GmbH PO Box 10 01 51 D 64201 Darmstadt Germany Im Tiefen See 45 D 64293 Darmstadt Germany H B M Tel 49 6151 8 030 Fax 49 6151 8039100 E mail support hbm com www hbm com measurement with confidence
5. 30000 otherwise the measured value will be output with Overflow or Underflow 7fff 4 or 8000p With NOV30000 the overflow reserve is still ca 2700d Caution With bus mode the output format must not be set to COFY HBM Operation with processor or terminal 16 HBM PW20i Communication commands COF16 to COF 28 Bus mode If you add the decimal number 16 to the COFO COF12 output formats specified above the PW20i switches to bus output mode A measured value is output The PW20i changes over to partially active mode each new measured value is stored in the output buffer but is not output The measured value is output to the bus when the Select command S is given The data output is without CR LF Example 2 PW20i ommand All PW20i are partially active listening but not transmitting Output as 2 byte binary output Highest sampling rate Continuous measurement in the PW20i Read measured value of 1st PW20i Read measured value of 2nd PW20i when response from first PW20i is received in full Read measured value of 1st PW20i when response from 2nd PW20i is received in full Read measured value of 2nd PW20i when response from first PW20i is received in full End data output Possible new PW20i 1 setting COF32 to COF44 binary data output without CRLF If you add the decimal number 32 to the COFO COF12 binary output formats specified above the PW20i switches to th
6. 345 Input coefficient 2 LIC 3 45 Input coefficient 3 Query LIC Response LIC0O 1000000 0 0 Effect Output of linearization coefficients in the sequence Coefficient 0 coefficient 1 coefficient 2 coefficient 3 CRLF Operation with processor or terminal 32 3 3 Measuring PW20i Communication commands Measuring includes all commands that act directly on a measured value e MSV e STP e ASF e FMD e ICR e TAR e TAV e TAS e MTD e ZTR e ZSE HBM Data output stop data output Filter setting Filter mode Sampling rate setting Taring Tare memory setting Gross Net selection Standstill monitoring Zero tracking Zero on startup Operation with processor or terminal PW20i Communication commands 33 MSV HBM Measured Signal Value Data output Range Integer 32767 Long Integer 8388607 ASCII 1000000 Factory setting ASCII Response time with fmd0 lt 2ICR x 1 67msec 1 67 msec with fmd1 lt 2 CR x ast 1 9 1 67msec 1 67msec Parameter 1 Password protection no Parameter backup no data to back up Query MSV 0 not with 2 wire mode Effect Continuous output of measured values until output cancelled with the command STP Query MSV 1 65535 Effect Delivers specified number of measured values The measured value is output in ASCII format or binary format see COF command Example ASCII format The output format for the measured value must be set beforeha
7. COF1 ASCII format Measured value Address Status 17 characters with COF9 Requisite baud rates for MSV 1 BDR Binary format 6 38400 19200 9600 4800 2400 1200 characters MSV 1 with COF0 COF4 Table 1 Baud rate dependent on measured value and output format Information for evaluating binary measured values N ae With data output in binary format the binary codes for CR and LF may occur within the bytes that are representing the measured value So the data output content must not be tested for the CR LF characters in the event of checking for an end to data transmission With binary output it is more a case of recording the number of characters received Also with binary output the control character CR LF is appended to the measured value sole exception MSV70 HBM Operation with processor or terminal PW20i Communication commands 19 CSM HBM Checksum Checksum in measurement status for binary output Range 0 1 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input CSM 0 1 Query CSM Effect The set function is output as a single digit decimal number 0 1 Checksum calculation can be used to find transmission errors during 4 byte binary output When CSM 0 checksum calculation in the measurement status is deactivated The standard measurement status is output see MSV With C
8. If the standstill monitoring is switched off MTDO no standstill monitoring will take place in the PW20i The standstill bit Bit 3 in the measurement status is then always 1 If the standstill monitoring is switched on MTD1 5 it refers to the nominal value set with the NOV command If the user scaling is switched off NOV 0 or NOV is used to select a scaling gt 100 000 then the standstill monitoring is implemented with 1 d sec for 100 000d scaling Information about whether the measured values during a second fall within the selected standstill range is transferred in the measurement value status information Transfer BIT 3 Operation with processor or terminal 48 PW20i Communication commands ZTR Zero tracking l Automatic zero tracking Range 0 1 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with TDD1 Input ZTR 0 1 0 Zero tracking deactivated 1 Zero tracking activated Query ZTR Response 0 1 Function Automatic zero tracking occurs for a gross or net measured value lt 0 5d in the range 2 of the nominal value of the scale NOV The maximum reset speed is 0 5d s at scale standstill Standstill detection can be set using the MTD command The unit d digit relates to the nominal value NOV When the NOV value is deactivated NOV 0 or the NOV value is 5100 000 d standstill monitoring is related to a nominal value of 100 000 d HBM O
9. and RSN 5 measured values O 5 10 9990 9995 10000 Operation with processor or terminal PW20i Communication commands 31 LIC HBM Linearization Coefficients Linearization The characteristic curve set as the factory setting is specified as a straight line at 2 points The user can adjust for a linearity error of the scale with the command LIC The PW20i has a third order polynomial for linearization Calculation output value LICO LIC1 x LIC2 x2 LIC3 x3 x input value With the aid of a third order polynomial even a linearity error with an inflection point can be corrected Increased measurement errors are to be expected outside the linearization interval The coefficients LICO LIC3 are entered as ASCII numbers with the LIC command The coefficients are defined when the scale is calibrated The calculation of the coefficients is not implemented in the PW20i but with the aid of the HBM program AED Panel 32 and the result is then loaded into the PW20i The exact procedure is described in the AED_Panel32 program Linearization Coefficient Compensation for a linearity error Range 0 1999990 Factory setting 0 1000000 0 0 LIC off Response time Output lt 15 msec Input lt 35 msec Parameter 2 4 Password protection yes Data backup with input Input LIC 0 3 coefficient Typical input example LIC 0 10 Input coefficient O LIC 1 1000345 Input coefficient 1 LIC 2
10. command ICR and the filter mode fmd and also the filter level asf if fmd 1 Filter mode fmd 0 Response time ca ms with MSV 0 1 2 3 4 5 6 7 Operation with processor or terminal PW20i Communication commands 35 HBM Filter mode fmd 1 Response time ca ms with MSV asf3 asf5 asf6 0 1 2 3 4 5 6 7 The output rates possible which are dependent on fmd asf and icr are shown in the ICR command description If you use the command MSV number a predefined number of measured values can be output The time between the output of two measured values is the measurement time The total recording time for the selected number of measured values will depend on the filter mode set fmd and is calculated as follows where fmd 0 and fmd 1 with asf 0 Measurement time ms number 2 CR 1 666 ms 1 666 ms where fmd 1 and asf 1 to 9 Measurement time ms number asf 2 CR 1 666 ms 1 666 ms With MSV 0 measured values are output continuously This output can only be stopped with the STP or RES commands or by switching off the voltage During continuous output no other parameters can be entered or queried Operation with processor or terminal 36 PW20i Communication commands In 4 byte binary output and in ASCII output the measurement status can be transferred with the measured value see COF com
11. number of characters are output The transducer type is always output as 15 characters the serial number is always 7 Operation with processor or terminal PW20i Communication commands 63 TDD Transmit Device Data Saving setting in EEPROM Reading EEPROM Range 0 2 Factory setting Response time TDDO lt 0 5 sec TDD1 lt 0 5 sec TDD2 lt 0 1 sec Parameter 1 Password protection TDDO yes TDD1 no TDD2 no Parameter backup no data to back up Input TDD 0 cold start the parameters are reset as per the following table After the factory settings have been made the settings are stored in a second write protected EEPROM The TDDO command copies the actual factory settings to the working EEPROM Write protected EEPROM working EEPROM p RAM The settings for communication such as address ADR and baud rate BDR as well as the standard meter TCR are not reset If there are no valid data in the write protected EEPROM the default parameter set is copied from the ROM EEPROM RAM This command overwrites parameters with the default values from the ROM HBM Operation with processor or terminal 64 HBM Command Factory setting PW20i Communication commands Remarks Address 31 Filter 1 Hz 9600 Baud even parity Measured value output decimal format address error status External checksum Checksum in measurement status off Password Unit Filter mode
12. on the bus for this application It must be remembered that the Response time of the load cells is used only once in the time calculation Master trans mission Response approx time PW20i 1 67ms ICRO PW20i trans xxCRLF zzCRLF missions HBM Operation with processor or terminal PW20i Communication commands 77 The Master can only send a new Select command once the measured value has been fully received This gives the following approximate query times COF2 ICRO 3 load cells Baud rate Output format Query time measured values for three PW20i load cells with ICRO Query time total character count x time for one character PW20i Response time These times should only be used as a guide Setting a parameter in all the connected PW20i The optimized procedure with the S98 command can also be used to set a parameter in all PW20i connected to the bus 1 Output broadcast command S98 all PW20i load cells execute the command but do not send a response 2 Output parameter command e g ICR3 3 Output TDD1 command when this setting is to be stored power failure protected 5 Sii select next PW20i load cell in order to e g test read the parameter This sequence can for example also be used when taring with the aid of the TAR command or when switching between gross and net output TAS HBM Operation with processor or terminal 78 Index A Address A
13. tare value MSV Ocrif net measured value TAS Ocrlf net is activated TAS Orrif select gross MSV 3000crlf measured value lies at 100 nom load of scale TAV 1500crlf query tare value unchanged HBM Operation with processor or terminal 46 PW20i Communication commands TAS Tare Set Gross net selection Range O 1 Factory setting 1 gross Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input TAS 0 1 0 net measured value value in tare memory subtracted von current measured value 1 gross measured value the value in tare memory is not offset The tare value remains unchanged when the gross net switch is made Query TAS Effect Current settings output HBM Operation with processor or terminal PW20i Communication commands MTD HBM 47 Motion Detection Standstill monitoring Range 0 5 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with TDD1 Input MTD 0 5 0 Standstill monitoring deactivated 1 Standstill monitoring 0 25 d sec from NOV value 2 Standstill monitoring 0 5 d sec from NOV value 3 Standstill monitoring 1 d sec from NOV value 4 Standstill monitoring 2 d sec from NOV value 5 Standstill monitoring 3 d sec from NOV value Query Effect MTD Output of set standstill increments 0 5
14. types and one separator TEX command Output type 1 The measured values are arranged one below the other for output Measured value1 CRLF Measured value2 CRLF Measured value n CRLF Output type 2 The measured values are arranged next to each other for output Measured val 1 separator Measured val 2 separator Measured val n CRLF Data output works with fixed output lengths see COF command COFO msv yyyy CR LF y binary a ae COF2 msv yy CRLF y binary Ca OE COF3 msv XXXXXXXX CR LF x ASCIl COF9 msv XXXXXXXX XX XXX CR LF x ASCIl The end label for data output is always CRLF or the separator defined using the TEX command But these characters must not be filtered out as end labels during binary output as these characters can also be included in the binary code of the measured value So as with binary output the bytes have to be counted In the subsequent syntax check the relevant places after CR or LF or the separator can then be queried Password protection PW20i password protection includes important settings for the characteristic curve of the scale and its identification Commands with password protection are only activated once the password is entered SPW command If the password is not entered these commands are answered with Operation with processor or terminal PW20i Communication commands 9 2 4 Command overview Function Device address Filter selection limit
15. up as an external trigger input for the trigger function TRC A low high flank at the trigger input activates the measurement procedure See also the MAV and TRC commands IMD The set function is output as a single digit decimal number 0 1 Operation with processor or terminal PW20i Communication commands 53 TRC Trigger Command Trigger settings Range 0 1 0 1 0 1599999 0 99 0 99 Factory setting 0 0 0 0 0 Response time lt 10 msec Parameter 5 Password protection no Parameter backup with TDD1 Input TRC P1 P2 P3 P4 P5 P1 0 Trigger function off P1 1 Trigger function on P2 0 Level triggering P2 1 External trigger input IN1 Trigger input IN1 is only active when IMD 1 P3 0 NOV Trigger level with P2 0 and NOV gt 0 P3 0 1599999 Trigger level with P2 0 and NOV 0 P4 0 99 Delay time P4 x 1 66ms x 2 CR with FMD 0 Delay time P4 x 1 66ms x 2 CR x ASF with FMD 1 and ASF gt 0 P5 0 99 Measurement time P5 x 1 66ms x 2 CR Measurement time P5 x 1 66ms x 2 CR x ASF with FMD 1 and ASF gt 0 Query TRC Response P1 P2 P3 P4 P5 CRLF HBM Operation with processor or terminal 54 HBM Function Note PW20i Communication commands The general function is described in the operating instructions Part 1 The position of the trigger level depends on the output scaling NOV When NOV 0 scaling off the trigger level is on the characteristic curve 0 1000000 W
16. yes Parameter backup with input Input Query Effect CWT lt calibration weight in 10000 gt If 100 of the end value cannot be reached when setting the user curve it is possible using the CWT command to set the PW20i with a load in the range from 20 to 120 of the required end value of the user curve partial load calibration CWT Response time lt 10 msec Value1 Value2crlf Value1 and Value2 are two 7 digit decimal numbers in the range 200 000 to 1 200 000 Value1 is the percentage of the max load at which the next LDW LWT adjustment is to be implemented Value2 is the percentage of the max load at which the last LDW LWT adjustment is to be implemented Value2 cannot be entered The CWT value used to implement the LDW LWT adjustment is part of the LDW LWT characteristic curve pair Operation with processor or terminal PW20i Communication commands Example ge Note Je SS HBM 25 with delivery the LDW value O the LWT value 1000000 and the CWT value 1000000 The LDW LDT user curve for a scale should be set so that a load of 100kg is assigned an output value of 1 million However only a 50kg balancing weight is available for the calibration For the calibration the CWT value is set to 500000 50 and then a LDW LWT calibration is implemented using 50 kg After the calibration the PW20i outputs at 50kg 500000 digit and at 100kg 1000000 digit as the measured value Following th
17. 0 Limit value1 is set The switching state of limit value 1 is only shown in the measurement status The limit value 1 switches dependent on the gross measured value Limit value 1 switches on with a gross measured value gt 120000 and off with gross measured value lt 110000 LIV 1 Output of limit value switch 1 settings in the sequence P1 P2 P3 P4 P5 LIV 2 Output of limit value switch 2 settings in the sequence P1 P2 P3 P4 P5 The switching function of the limit value switch is inverted when P4 is smaller than P5 When P4 lt P5 the status bit is set as long as the measured value is smaller than P4 When P4 5 P5 the status bit is set as long as the measured value is greater than P4 see example The switching hysteresis is determined by the difference between P4 and P5 Operation with processor or terminal 58 PW20i Communication commands 3 5 Special functions DPW Define Password Define password Range 1 7 digits or numbers ASCII characters Factory setting AED Response time lt 70 ms Parameter 1 Password protection no Parameter backup with input Input DPW Password With this command the user can enter any password with maximum 7 digits All ASCII characters are permitted The input must be made in quotes HBM Operation with processor or terminal PW20i Communication commands 59 SPW Set Password Write enable for all password protected parameters Ra
18. 0 6 240 4 10 5 13 gt 90 gt 34 7 295 3 5 8 10 gt 90 gt 34 8 330 3 7 9 gt 90 gt 30 9 365 2 5 6 2 8 gt 90 gt 30 With ASFO the filter is deactivated The average value determination ICR does not influence the settling time of the filter The specified settling times refer to the PW20i The total settling time is also dependent on the mechanical construction of the load cell on the dead load of the scale and on the weight to be weighed Operation with processor or terminal 40 PW20i Communication commands FMD Filter mode Filter mode Range 0 1 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input FMD 0 1 Input of filter type as decimal number of 0 or 1 0 Standard filter 1 Fast settling digital filter Query FMD Effect Output of set filter type O or 1 The description of the filter type can be found in the ASF command description HBM Operation with processor or terminal PW20i Communication commands 41 Internal Conversion Rate ICR Sampling rate Range 0 7 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input ICR 0 7 Input of sampling rate as decimal number from 0 7 The integration time determines the output data rate of the measured values and therefore also the response time for a measurement query
19. 0021 2 PW20i 4273 Initialize the master interface with 9600 Bd 8 e 1 Output broadcast command S98 Set required address with the command ADR e g ADR01 0021 Set required address with the command ADR e g ADR02 4273 etc Save addresses power failure protected with the command TDD1 Caution With S98 none of the PW20i respond but all the PW20i execute the command Load cells that do not respond in this manner may have a different baud rate They can be recognized via a bus scan with the possible baud rates Operation with processor or terminal PW20i Communication commands 73 HBM Once all the addresses have been set correctly and there is a uniform baud rate the bus is ready for action The output format must now be set for the measurement query The output format must be set in all the modules before the MSV command can be used for data output 2 Output broadcast command S98 all PW20i load cells execute the command but do not send a response 2 Output command for output format e g COF3 for ASCII output 3 Command TDD1 when this setting must be stored power failure protected Changing the baud rate The PW20i load cells can work at different baud rates The settings can only be modified via the serial interface using the BDR commana In bus mode the baud rate of all the connected nodes must be the same To make sure that the PW20i load cells in a bus are set to the desire
20. 3 1 HBM Individual command descriptions Interface commands asynchronous serial Interface characteristics Start bit 1 Word length 8 Bit Parity none even Stop bit 1 Software handshake XON XOFF is possible Baud rate 1200 2400 4800 9600 19200 38400 57600 115200 baud The asynchronous interface of the PW20i is a serial interface i e data is transferred bit by bit one after the other and asynchronously Asynchronous means that the transmission works without a clock signal A start bit is set before each data byte Then come the word bits a parity bit for the transmission check optional and a stop bit Word length 8 data bits 1 bit 1 bit BAKA Parity Stop 1 character Fig 1 Composition of a character As the data is transferred serially the speed of transmission must match the speed of reception The number of bits per second is called the baud rate The input buffer is synchronized with the start bit for every character transferred Next come the data bits these all have the same length When the stop bit is reached the receiver goes into the wait state until it is reactivated by the next start bit The number of characters per measured value ranges between 2 and 17 and depends on the output format selected COF command see also COF command The interface must be configured to establish communication between the PW20i and the computer The
21. B1561 1 0 en Operating instructions PW20i Part 2 Communication commands I W S 2 PW20i Communication commands Contents Safety INO MANONG apa NANA AA Ah KNA PAANAN AUNG AG 1 Introduction ssia neea a a e a a ee a a eee ee eee 5 2 Command set for the PW20i 22 2ccceccieeencrcnerewarteeene rete eraeneane nee GE 21 Command format sses sessies esk papei e pe ea eee NAN NG a E E EEG 6 2 2 Response to commandS 443R ENE A eoaePenae nee eee dee ee eee Reds m 2 3 Output types for measured values teen eens 8 2 4 Command overview 2 cciaaseoeeieedeonstavivantiavinevedatewansbadeaand Q 3 Individual command descriptions eee eee eee eee eee 16 3 1 Interface commands asynchronous serial eee 115 3 2 Adjustment and calibration 062 6sc eee eee ee eee eee ees 22 3 3 MGASUNIG PAA 32 3 4 Trigger functions and limit values c eee 50 3 5 Special functions 2247 ma mna akma NGAAAG LUAND GWA KIS NAAN uaneacaenceeuateanend 581 3 6 Error messages ka pak isona kara nison i ee geeks GN GNG DRI EE aeae eeaeee dues 677 3 7 Commands for Legal for trade applications 68 3 8 Other commands 2nceiecesenesandnde PhAWDBENLADEANON exotesepegyebes saene 70 3 9 Communication examples 00 00 cece eee eee eee 731 Indek owe weer Te eT Te et eer eT eT Terr AY 781 Operation with processor or terminal HBM PW20i Communication commands 3 HBM Operat
22. DR 22 222 121 Amplifier Signal Filter ASF 39 B Baud Rate BDR 2 2 00 13 C Calibration Weight CWT 00005 241 Checksum CSM 2 220 19 Configurate Output Format COF 144 Cyclic Redundancy Check CRC 70 D Define Password DPW 22 0055 59 E Engineering Unit ENU 61 Event Status Register ESR 67 F Filter mode FMD 2 2 22 4M l Identification IDN cee eee eee 627 Input Mode IMD 0 0 e eee eee ee 527 Internal Conversion Rate ICR 41 HBM Index L Legal for Trade LFT cee eee eee 687 Limit Values LIV eee eee eee 56 Linearization Coefficients LIC 37 Load cell Dead Load Weight 29 Load cell weight aa 21 M Measured Alternative Value MAV 57 Measured Signal Value MSV 33 Motion Detection MTD 47 N Nominal value NOV 00 cee eee eee 29 P Port Set and Read POR 0a St R Resolution RSN aeaa 39 Restart RES sietas 0 0 cee ee ence eee 69 S Saving the setup parameters 64 Select AA PA 21 Set Password SPW aaa 59 DIOP STP suss misline Baa kalala Re 377 Operation with processor or terminal Index Index T Taro TAR aa paaa Ba JA LAAN 43 Tare Set TAS 2 22 a 461 Tare Value TAV 2
23. PW20IR2 20K Load cell description Identification on the type plate PW20i YY ZZ ZZ 5K 10K 20K max capacities K kg YY Interfaces R2 RS 232 R5 RS 485 Example PW20i R5 10K Load cell PW20i with interface RS 485 and max capacity 10 kg HBM Operation with processor or terminal 2 2 1 HBM PW20i Communication commands Command set for the PW20i Commands can be roughly divided into e Interface commands ADR BDR COF CSM Sxx TEX e Commands for adjustment and scaling SZA SFA LDW LWT NOV CWT LIC e Commands for measurement operation MSV MAV ASF ICR TAR TAS TAV FMD MTD ZSE ZTR e Inputs and trigger functions IMD POR TRC MAV e Special commands TDD RES DPW SPW IDN ENU ESR e Commands for legal for trade applications LFT TCR CRC Command format General advice Commands are not case sensitive so either format can be used for input Each command entry must be concluded by a delimiter This can either be a line feed LF or a semi colon 5 If an end label is all that is sent to the PW20i the PW20i input buffer is cleared The data provided in round brackets for the commands are mandatory and must be entered Parameters in pointed brackets lt gt are optional and do not have to be provided The brackets themselves are not part of the input Text must be enclosed in quotes With numeric input preceding zeroes are suppressed Numbers can either be en
24. SM 1 a checksum EXOR is formed over the measured value covering three bytes and this is output instead of the measurement status This checksum output can only be used for output formats COF8 and COF 12 i 16 i 0 1 7 Operation with processor or terminal 20 TEX HBM PW20i Communication commands Terminator Execution Separator for data output Range 0 255 Factory setting 172 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input TEX 0 255 The required separator is input decimally as a ASCII character e g comma 2Cy 44 D _ input TEX44 H Hexadecimal D Decimal Every ASCII character from 0 127p 0 7Fp can be used as a separator The separator is placed between the parameters for data output also see MSV and COF commands Example tex 44 data output 0123456 12 000 0123457 12 000 etc with COF9 If the chosen ASCII character is entered with an offset of 128 above example comma 44 p 128 p 172 p _ input TEX172 then the parameters of a measured value will continue to be separated by a comma but CRLF will be output at the end of the measured value Example tex 172 Data output 123456 12 000 123457 12 000 etc Query TEX Effect The set separator is output as a three digit decimal number 0 255 Operation with processor or terminal PW20i Communication commands 21 HBM Select Selecting of PW20i
25. arity 0 no parity bit 1 parity bit even Caution The response is given at the new setting baud rate parity Once the baud rate is changed communication is not possible initially The processor also has to be changed over to the newly selected baud rate setting For the change in baud rate to become permanent it has to be saved in the EEPROM with the TDD1 command This procedure ensures that you do not set baud rates in the PW20i which are not supported by the remote station If the new baud rate entry is not saved the PW20i will go back to the previously valid baud rate after a reset or a power up Query BDR Effect Output of set baud rate Parity bit identifier Example BDR 9600 1crlf equals 9600 Baud parity bit even Operation with processor or terminal 14 PW20i Communication commands COF HBM Configurate Output Format Output format for data outputs Range 0 255 Factory setting 9 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input COF 0 255 Input of output format for measured value command MSV The available formats and the decimal number to be entered are listed in the following table Query COF Effect Output of selected output format as three digit decimal number from 0 255 COF formats Inputs from COFO to COF15 result in the following combinations e MSB highest value position e LSB lowest value po
26. ation examples HBM Settings for bus mode for RS485 interface only The PW20i load cell is able to work with up to 32 modules in one bus The interface wires RS485 4 wire are connected in parallel to a physical circuit the connection to the PC is implemented with an interface converter e g HBM 1 SC232 422A The individual PW20i function as slaves i e without prompting by the bus master e g PC or PLC the PW20i remain inactive on their transmission line The master selects a PW20i by using the SELECT command S00 31 This is why it is essential to enter a communication address for each PW20i load cell before connecting to the bus Each address may only be assigned once in the bus factory setting is 31 There are two options for entering the communication addresses 1 Connect the load cells to the bus one after the other Connect the first PW20i load cell to the bus line the factory setting is ADR31 baud rate 9600 Initialize the master interface with 9600 Bd 8 e 1 Output command S31 Set required address with the command ADR e g ADR01 Select the PW20i load cell with the new address S01 Save address power failure protected with the command TDD1 Connect next PW20i load cell to the bus output S31 set ADRO2 etc or 2 Enter addresses when all PW20i load cells are connected to the bus Read production numbers of PW20i load cells as given on type plate e g 1 PW20i
27. ave no relationship with MSV xx or MSV 0 Transfer rate too low Measured value output is not conclusive in the chosen configuration When several conditions occur simultaneously the measurement status is equal to the sum of the resp bit values The output measured values are not equidistant and must not be used to calculate an FFT HBM Operation with processor or terminal PW20i Communication commands 37 Sup Sto Stop data output This command ends data output STP only works on the MSV command If a measured value has started it is output in full HBM Operation with processor or terminal 38 HBM PW20i Communication commands Amplifier Signal Filter Filter selection limit frequencies Range 0 9 Factory setting 5 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input ASF 0 9 There are two filter ranges dependent on the filter mode FMD 0 standard filter selectable filter levels 0 8 FMD 1 fast settling digital filter selectable filter levels 0 9 Query ASF Effect Output of set filter level 0 9 The PW20i has a multi level filter chain e an average value determination over 2 measured values with 1200 Hz sampling fixed setting e Standard filter FMDO or a fast filter FMD 1 limit frequency selectable via ASF sampling rate fixed 600 Hz e an average value determination for sampling rate reduction
28. cale scale characteristic curve Range 0 1599999e6 Factory setting 1000000 Response time lt 15 msec 4 2s Parameter 1 0 Password protection yes Parameter backup with input Input Effect Input Query Effect Note LWT Response time lt 4 2 sec This command is used to measure the output signal when the scale is loaded with the user curve end value This measured value is offset with the previously determined LDW value to create a new characteristic curve LWT lt End value gt Response time lt 1 5 sec Instead of taking over the output signal the value for the loading of the scale with the user characteristic curve end value is entered It is offset with the previously determined LDW value to create a new characteristic curve LWT Response time lt 15 msec The value used in the PW20i to calculate the user curve for the end value is output as 7 digits with sign e g 0800345 crif The value is not converted via NOV If the LDW LWT calibration is not implemented with a 100 input signal the CWT value must be set first see CWT Calibration Weight Operation with processor or terminal 28 PW20i Communication commands There are two ways of setting a user curve 1 Measuring the user characteristic curve CWT LDW LWT 1 1 Enter password with command SPW 1 2 Enter NOV 0 scaling off 1 3 Set the filter ASF so that the display is as smooth as possible 1 4 Enter the CWT lt Calibrati
29. cute the subsequent commands No PW20i responds This continues until an individual PW20i is addressed with SOO S31 A measured value query in the bus can be implemented as follows e S98 all PW20i selected e MSV Measured value query all PW20i generate the measured value and place this value in the output buffer after the integration time ICR but no PW20i sends e S01 PW20i with address 01 is selected and outputs the measured value e S02 PW20i with address 02 is selected and outputs the measured value etc 3 2 Adjustment and calibration HBM The following commands are used to set the default characteristic curve and the user curve Commands for adjusting the user characteristic curve LDW LWT Command for adjusting the user curve characteristic with partial load CWT The command NOV is used to scale the measured value Characteristic curve setting The PW20i initially works with a default curve set to the max load of the PW20i The default characteristic curve can be restored at any time with TDDO The user can adapt the PW20i characteristic curve to their requirements user characteristic curve with the command pair LDW LWT Using the command CWT the user characteristic curve can also be set with partial load Caution The characteristic curve commands LDW and LWT must be entered or executed in the sequence LDW followed by LWT The input data is only offset when the two parameters have been entered or measur
30. d baud rate during initialization activation of the system in this example 9600 please proceed as follows 1 Set the baud rate of the master interface to 2400 Bd 8 data bits 1 parity bit even 1 stop bit clears the input buffer of the PW20i selects all PW20i load cells in bus output of required baud rate wait ca 150 ms 2 Output of command sequence S98 BDR9600 PAA NT 3 Set the baud rate of the master interface to 4800 Bd 8 data bits 1 parity bit even 1 stop bit clears the input buffer of the PW20i selects all PW20i load cells in bus output of required baud rate wait ca 150 ms 4 Output of command sequence S98 BDR9600 PAA 5 Set the baud rate of the master interface to 19200 Bd 8 data bits 1 parity bit even 1 stop bit clears the input buffer of the PW20i selects all PW20i load cells in bus output of required baud rate wait ca 150 ms 6 Output of command sequence S98 BDR9600 PAA AA Operation with processor or terminal 74 HBM PW20i Communication commands 7 Set the baud rate of the master interface to 38400 Bd 8 data bits 1 parity bit even 1 stop bit 8 Output of command sequence clears the input buffer of the PW20i S98 selects all PW20i load cells in bus BDR9600 output of required baud rate 9 Set the baud rate of the master interface to 9600 Bd 8 data bits 1 parity bit even 1 stop bit 10 Output of command sequence clears the in
31. e calibration the response to CWT is 500000 500000crlf If the values for LDW and LWT have to be input again at some time the CWT value must be entered first followed by the value for LDW and then the value for LWT Operation with processor or terminal 26 LDW HBM PW20i Communication commands Load cell Dead Load Weight User charact curve zero point scale charact curve Range 0 1599999e6 Factory setting 0 Response time lt 15 msec 4 2s Parameter 1 Password protection yes Parameter backup after input of LWT Input LDW Response time lt 4 2 sec This command is used to measure and save the output signal of the unloaded PW20i It is only offset after the parameters for LWT are entered Input LDW lt zero point gt Response time lt 15 msec The value is entered here instead of the output signal being taken over The value entered is stored but only offset after the parameter for LWT is entered Query LDW Response time lt 15 msec Effect The value used in the PW20i to calculate the user curve for the unloaded scale is output as 7 digits with a sign e g 0000345 crlf The value is not converted via NOV Note If the LDW LWT calibration is not implemented with a 100 input signal the CWT value must be set first see CWT Calibration Weight Operation with processor or terminal PW20i Communication commands HBM 27 Load cell weight User characteristic curve full s
32. e following output modes for the measurement data With binary data output the end label CR LF is omitted so that only 2 or 4 characters per measured value are output This action increases the output speed of the measured values Format Length Sequence for data output MSB before LSB LSB 0 no status MSB LSB LSB before MSB LSB 0 no status LSB MSB MSB before LSB LSB Status CRC LSB before MSB LSB Status CRC Operation with processor or terminal PW20i Communication commands 17 HBM COF64 COF76 2 wire bus mode If you add the decimal number 64 to the COFO COF12 output formats specified above the PW20i switches to 2 wire bus mode This means that when commands are entered the PW20i no longer responds with 0 or Only command queries such as ASF obtain the response with the parameter or in the case of MSV with the measured value The command MSV 0 continuous measured value transmission must not be used in this mode as otherwise it will no longer be possible to stop this output unless you switch off the supply voltage COF128 to COF 140 continuous output after power on aution Not for bus mode If you add the decimal number 128 to the COFO COF12 output formats specified above the PW20i switches to continuous output mode After a power up or RES command the PW20i sends out the measured values without an MSV prompt Continuous output can be deactivated wi
33. ed in pairs When defining the characteristic curve scaling must be deactivated NOVO Operation with processor or terminal PW20i Communication commands 23 Once values for the zero point and end value of the user curve have been successfully entered or measured the range LDW 5 LWT with NOV 0 is assigned to the following number ranges Output format COF Output with max load NOV 0 NOV gt 0 2 byte binary 20000 NOV value 4 byte binary 5120000 NOV value ASCII 1000000 NOV value With the 2 byte binary output the NOV value must be lt 30000 otherwise the measured value will be output with Overflow or Underflow 7fff 4 or 8000p H Hexadecimal With NOV30000 the overflow reserve is only about 2700 digits Set user characteristic curve with LDW LWT Action sequence Command Enter password SPW AED Load zero load scale LDW Load max load scale LWT 4 Digit Default characteristic curve 1000000 COF3 700000 100000 Load L Ln isti Ln 1000000 User characteristic curve n max load COF3 p 07 Load L Ln Range application Fig 2 Setting the user characteristic curve HBM Operation with processor or terminal 24 HBM PW20i Communication commands Calibration Weight Calibration weight Range 200 000 1 200 000 20 120 Factory setting 1000000 100 Response time lt 10 msec Parameter 1 2 Password protection
34. ee LFT command The maximum count is 8388607 7F FF FF hex If this count is reached the counter stops then at the next MSV data output only overflow values are output This situation can only be remedied at the factory Operation with processor or terminal 70 PW20i Communication commands CRC Cyclic Redundancy Check Checksum Range 8 388 607 Response time lt 50 msec Parameter 1 Password protection no Parameter backup with input Query CRC Effect xxxxxxxx Crif 8 characters crif Input CRCxxxxx5 Effect Ocrlf This command gives the user the opportunity to externally calculate a checksum over all the PW20i parameters and store it in the PW20i It is up to the user how this checksum is calculated If the command LFT1 has activated the application subject to mandatory calibration the change to the CRC also increases the standard meter TCR This allows every attempted manipulation of the PW20i parameters to be detected HBM Operation with processor or terminal PW20i Communication commands 71 3 8 Other commands The commands SZA SFA TCZ TCC and TMP are commands used within HBM The settings for SZA SFA TCZ TCC and TMP are set by HBM and must not be changed The commands listed here are only included in the PW20i for reasons of compatibility They have no function COR STR ACL CAL HBM Operation with processor or terminal 72 PW20i Communication commands 3 9 Communic
35. ell does not respond to this Select command Measurement query in bus mode The previous chapter has ensured that all PW20i load cells are ready for bus mode and have been detected by the bus scan The output format for a simple measurement query with the command MSV has been set with the COF command The command sequence is now S00 MSV The PW20i load cell with the address 00 responds with the measured value S01 MSV The PW20i load cell with the address 01 responds with the measured value etc Operation with processor or terminal 76 PW20i Communication commands This gives the following approximate query times Master transmission S00 MSV 9 characters 1 character Pause Response time PW20i ca 6 7ms with ICR2 FMDO PW20i Transmission xxCRLF 4 characters with COF2 6 characters with COF8 10 characters with COF3 Baud rate Output format Query time measured value for a PW20i load cell with ICR2 These times should only be used as a guide For a faster measurement query using the command MSV the command sequence is S98 MSV All PW20i load cells generate a measured value but do not respond S01 The PW20i load cell with the address 01 responds with the measured value S02 The PW20i load cell with the address 02 responds with the measured value S03 The PW20i load cell with the address 03 responds with the measured value etc The following protocol displays the data traffic
36. following commands are available in the PW20i for this purpose ADR BDR COF TEX S Operation with processor or terminal 12 HBM PW20i Communication commands Address Device address Range 0 31 Factory setting 31 Response time lt 10 msec Parameter 2 Password protection no Parameter backup with command TDD1 Input ADR new address lt Serial No gt Input of device address as decimal number 0 31 The serial number can also be entered as an optional second parameter The new device address is then only entered for the PW20i with the serial number specified This then means that if there are several PW20i with the same address initializing bus mode it is possible to change device addresses without addressing several PW20i The serial number must be given in quotes as for the IDN command Example ADR25 007 CRLF Query ADR Effect Input of device address as decimal number 0 31 Operation with processor or terminal PW20i Communication commands 13 BDR HBM Baud Rate Baud rate Baud rates 1200 2400 4800 9600 19200 38400 57600 115200 Factory setting 9600 Baud and parity bit even Response time lt 10 msec Parameter 2 Password protection no Parameter backup with command TDD1 Input BDR lt Baud rate gt lt Parity gt Input required baud rate as decimal number The following baud rates are possible 1200 2400 4800 9600 19200 38400 Baud Input required p
37. frequencies Baud rate Output format for data outputs Checksum Checksum in measurement status for binary output Calibration weight Define password User definition of units Output of error messages Filter mode Sampling rate Identification of transducer type and serial number Set the function of the inputs User characteristic curve zero point scale chracteristic curve Legal for trade application Linearization User characteristic curve full scale scale charact curve Measured value trigger function Data output Standstill monitoring Resolution of the user characterisic curve Set and read digital inputs and outputs Reset Increment Selection of PW20i in bus mode PERPPRREPERRERPEPREEDEP pag RP HBM Operation with processor or terminal 10 PW20i Communication commands SPW Write enable for all password protected parameters STP Stop data output TAR Tare TAS Gross net selection TAV Tare value TCR Legal for trade counter TDD1 2 Saving setting in EEPROM Reading EEPROM TDDO Factory setting TEX Separator for data output TRC Trigger settings ZSE Zero on start up ZTR Automatic zero tracking Save with TDD1 otherwise on input Password protection via commands DPW SPW HBM Operation with processor or terminal PW20i Communication commands 11 3
38. hen NOV3 gt 0 the trigger level is in the range O NOV The external trigger is only enabled again when the output value has been calculated no re trigger function The trigger status ext or level trigger is output for IMD1 in the measurement status of MSV or MAV in bit 6 The bit becomes active when triggering occurs it becomes inactive when a new trigger value MAV has been calculated This allows the trigger function to be monitored over time If the COF command 128 140 has been used to select automatic output and the trigger function is activated the PW20i outputs the measured value once only after triggering and subsequent measurement This means that it is not necessary to use the MAV command to query the measured value The connected processor only needs to receive this measured value To set this operating mode see the COF command COF128 to COF 140 continuous output after power on Caution Not for bus mode Example external triggering with automatic output Set PW20i parameters ASF ICR TRC1 1 0 20 5 Activate external trigger COF128 i i dependent on binary ASCII output see COF command parameter setting not possible the result is automatically output after every trigger event without MAV command STP Stops automatic output TDD1 Power failure protected storage of automatic output in EEPROM RES Restarts automatic output mi the result is automatically output after every trigger event
39. in bus mode Range 0 31 98 Factory setting Response time lt 10 msec Parameter 1 Password protection no Parameter backup no data to back up Input S 00 31 98 The Select command does not generate a response When several PW20i are connected together to a bus this can be used to address them individually or jointly One PW20i is always active after reset or power up except when COF5 127 and in bus mode this must be addressed by the Select command so that the other bus nodes do not respond If there is only one PW20i the S command is not needed The command ADR can be used to assign up to 31 addresses 00 31 command alone does not generate a response Only when it is used together with another command does the selected PW20i respond Exception in bus mode COF16 COF28 after MSV 0 Selection Effect for PW20i Effect for PC s00 to s89 Only the PW20i with the specified address 1 1 communication with a selected PW20i executes all the commands and responds All the other PW20i only understand Select commands S00 to S99 and do not respond All the PW20i execute all the s98 commands but do not respond Example Select 00 Command 1 Command 2 n Select 01 Command 1 etc Operation with processor or terminal 22 PW20i Communication commands Command S98 is intended for special functions broadcast All PW20i connected to the bus are addressed All PW20i exe
40. ion with processor or terminal 4 PW20i Communication commands Safety informations See operating instructions Part 1 All the factory settings are stored at the factory so that they are safe from power failure and cannot be deleted or overwritten They can be reset at any time by using the command TDDO For more information see Individual Command Descriptions The factory set production number must not be changed Residual risks are indicated in these mounting instructions by the following symbols Symbol CAUTION Meaning Possible dangerous situation Warns of a potentially dangerous situation in which failure to comply with safety requirements could result in damage to property or some form of physical injury Symbols for operating instructions and useful information vig Syma ADS NOTE Means that important information about the product or its handling is being given HBM Operation with processor or terminal PW20i Communication commands 5 1 Introduction The PW20i load cells are part of the digital load cell family that digitally conditions measurement values and networks them with bus capability These operating instructions describe the function and connections of the PW20i digital load cells This section describes the commands for serial communication These operating instructions apply to the following designs of the PW20i digital load cells PW20IR5 5K PW201R2 5K PW20IR5 10K PW20IR2 10K PW20IR5 20K
41. ion with processor or terminal PW20i Communication commands 75 HBM Determining bus occupancy Bus Scan It is often useful each time the bus is activated or when the PW20i load cell fails to respond to determine the bus configuration The address occupancy of the bus can be determined with the aid of Bus Scan This is on condition that all the modules are set to the same baud rate 1 Initialization of master interface with set PW20i baud rate 3 Scan an address with the command sequence S00 Select Address X output of invalid command The PW20i load cell sensed at the address responds with CRLF because it does not know the command If there is no response after a period of ca 100 ms there is no PW20i present at this address If the master receives undefined characters or no character there may be a bus malfunction or multiple occupancy of the address The bus master must react accordingly 4 Repeat point 2 with subsequent addresses 01 31 If only a few load cells are connected and their addresses known the bus scan can be reduced to the known addresses Once all the PW20i load cells are successfully established as bus nodes the PW20i load cell identification string can be read in measuring point identification and production number The time out setting for the master interface driver is crucial for the speed of the bus scan The Select command needs max 20 30ms for output at 2400 baud The PW20i load c
42. lso see TAV command and subtracted from the measured value and from all subsequent measured values Operation with processor or terminal 44 TAV HBM PW20i Communication commands Tare Value Tare value Range 0 4 1638399 Factory setting 0 Response time lt 20 msec Parameter 1 Password protection no Parameter backup with command TDD1 Input TAV Tare value Enter tare value 7 digits with sign max 8 388 607 The value is on the LDW LWT characteristic curve scaled with the NOV parameter 0 NOV After the commands SZA SFA or LDW LWT have been used for characteristic curve input the tare memory is cleared content 0 Query TAV Effect The content of the tare memory is output The tare value is converted to the NOV value Output format Nominal Maximum Nominal Maximum Measured value taring range with taring range with taring range with taring range with with NOV gt 0 NOV gt 0 NOV 0 NOV 0 max load 2 byte binary NOV value 15096 NOV 1000000 1 599999 value 4 byte binary NOV value 150 NOV 1000000 1 599999 value ASCII NOV value 15096 NOV 1000000 1 599999 value Operation with processor or terminal PW20i Communication commands 45 Example NOV3000 scale scaling TAS1 Gross output activated MSV 1500crif measured value lies at 50 max load of scale TAR Tare and select net output TAV 1500crlf query
43. mand Bit assignment in measurement status with IMD 0 Bit value in status byte Significance 1 Net Overflow Tare value too high 2 Gross Overflow Scaling too sensitive 4 ADU Overflow ADU overdriven Load gt nominal value reserve 8 Standstill Bit set Standstill see command MTD 16 limit value 1 Internal limit value see command LIV 32 limit value 2 Internal limit value see command LIV 192 measured values have no relationship with MSV xx or MSV 0 Transfer rate too low Measured value output is not conclusive in the chosen configuration When several conditions occur simultaneously the measurement status is equal to the sum of the resp bit values The output measured values are not equidistant and must not be used to calculate an FFT Bit assignment in measurement status with IMD 1 Bit value in status byte 1 Net Overflow Significance Tare value too high 2 Gross Overflow Scaling too sensitive 4 ADU Overflow ADU overdriven Load gt nominal value reserve 8 Standstill Bit set Standstill see command MTD 16 limit value 1 Internal limit value see command LIV 32 limit value 2 Internal limit value see command LIV 64 Trigger only when Bit 7 is not set Triggering has occurred Remains set until the trigger output value MAV is generated 192 measured values h
44. nd via the command COF The measured value is output in relation to the particular measuring range The measured value can be a gross or net measured value command TAS This command generates responses with constant length The output length for the command MSV is dependent here on the output format see COF command Output format PW20i response Character count Binary 4 Byte yyyy CRLF y binary Binary 2 Byte yy CRLF y binary ASCII COF3 XXXXXXXX CR LF x ASCII ASCII COF9 XXXXXXXX XX XXX CR LF x ASCII CR Carriage Return LF Line Feed Operation with processor or terminal 34 HBM PW20i Communication commands Separator can be adjusted command TEX selected separator 1001500 25 000 a PSC IN _______ Measurement status optional COF 2 Byte address 00 31 optional COF 8 Byte measured value pos sign blank The output scaling is dependent on the parameter of the command NOV Output format Output value with max load NOV 0 NOV gt 0 2 byte binary 20000 NOV value 4 byte binary 5120000 NOV value ASCII 1000000 NOV value With the 2 Byte binary output the NOV value must be lt 30000 otherwise the measured value will be output with Overflow or Underflow 7fff 4 or 8000p H Hexadecimal With NOV30000 the overflow reserve is only about 2700 digits The response time during the measurement query is determined by the integration time
45. nge The password specified with DPW Factory setting AED Response time lt 10 msec Parameter 1 Password protection no Parameter backup no data to back up Input SPW Passwd The command SPW with the correctly entered password authorizes data input with all commands The command SPW with an incorrect password inhibits data input for protected commands A password is not necessary for output Password input is case sensitive The use of protected commands is also inhibited after RES or power up The following commands are protected by a password CWT LDW LWT LIC NOV SFA SZA TDDO HBM Operation with processor or terminal 60 PW20i Communication commands Reset Range Factory setting Response time lt 3 S Parameter Password protection no Parameter backup no data to back up The RES command restarts the device warm restart This command does not generate a response All the parameters are set in the way in which they were saved the last time the TDD command was used i e the EEPROM values are transferred to the RAM HBM Operation with processor or terminal PW20i Communication commands 61 ENU Engineering Unit User definition of units Range 4 digits or numbers ASCII characters Factory setting none Response time Output lt 15 msec Input lt 40 msec Parameter 1 Password protection no Parameter backup with input Input ENU abcd Input of a
46. ommand TDD1 Input NOV lt Value gt Query NOV Response time lt 10 msec Effect The value stored in the PW20i is output as 7 digits with sign e g 1001000 crif The NOV value is used to scale the output value during data output When NOV 0 this output scaling is deactivated ASCII data output is scaled at the factory to 1000000 at max load If a data output of 2000 digits is required at max load the nominal value NOV2000 must be set with this command This scaling does not modify the input parameters or the tare value Output format COF Output with max load NOV 0 NOV gt 0 2 byte binary 20000 NOV value 4 byte binary 5120000 NOV value ASCII 1000000 NOV value Note For 2 byte binary output the NOV value must be lt 30000 otherwise the measured value will be output with Overflow or Underflow 7fffH or 8000p H Hexadecimal With NOV30000 the overflow reserve is only about 2700 digits Operation with processor or terminal 30 HBM PW20i Communication commands Resolution Increment Range 1 2 5 10 20 50 100 Factory setting 1 Response time lt 10 msec Parameter 1 Password protection no Parameter backup With command TDD1 Input RSN lt value gt Query RSN Response time lt 10 msec Effect The value stored in the PW20i is output with 3 digits e g 001 crif The increment limits the measured value resolution during output Example NOV 10000 d
47. on weight gt if setting with a partial load 1 5 Unloaded scale enter LDW the output signal for the unloaded scale is measured 1 6 Load scale enter LWT the output signal for the loaded scale is measured and the user curve calculated 1 7 Set ASF and NOV as required for the application power failure protected backup of parameters NOV ASF with the command TDD1 2 Input of the user characteristic curve CWT LDW LWT 2 1 Enter password with command SPW 2 2 Enter NOV 0 scaling off 2 3 Enter CWT 1000000 partial load calibration off 2 4 Switch off user curve with LDWO and LWT1000000 2 5 Set the filter ASF so that the display is as smooth as possible 2 6 Scale unloaded wait for standstill 2 7 Determine measured value with MSV note Value1 for LDW 2 8 Load the scale with max load wait for standstill 2 9 Determine measured value with MSV note Value2 for LWT 2 10 Enter CWT if the LWT value is not equal to 100 max load 2 11 Enter new curve with LDW lt Value1 gt then LWT lt Value2 gt 2 12 Set ASF and NOV as required for the application power failure protected backup of parameters NOV ASF with the command TDD1 HBM Operation with processor or terminal PW20i Communication commands 29 NOV VIN Pa s Dy HBM Nominal value Resolution of the user charact curve Range 0 1599999e6 Factory setting 0 switched off Response time lt 10 msec Parameter 1 Password protection yes Parameter backup with c
48. peration with processor or terminal PW20i Communication commands HBM 49 Zero Setting Zero on start up Range 0 4 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with input Input ZSE 0 4 0 Zeroing deactivated 1 Zeroing range 2 96 of the NOV value 2 Zeroing range 5 96 of the NOV value 3 Zeroing range 10 of the NOV value 4 Zeroing range 20 of the NOV value Query Function ZSE Response 0 4 After cutting in the voltage after a RESET or after the command RES zeroing in the selected range is performed after about 2 5s at standstill A change to the zero on startup correction range only takes effect after the voltage cut in or after the RES command If there is no standstill or if the gross value falls outside the selected limits zero is not set The internal zero memory is always cleared before automatic zeroing If the gross value at standstill falls within the selected range the gross value is accepted into the zero memory Zero memory cannot be read out Scale standstill is fixed at 1d s The unit d digit relates to the nominal value NOV When the NOV value is deactivated NOV 0 or the NOV value gt 100 000 d standstill monitoring is then related to a nominal value of 100 000 d Operation with processor or terminal 50 3 4 Trigger functions and limit values HBM This group includes the following command
49. put buffer of the PW20i 11 Command TDD1 when this setting must be stored power failure protected It is absolutely essential to output the semicolon before command S98 because if the PW20i have been triggered at different baud rates there may be undefined characters in the PW20i input buffer These will be rejected when the semicolon is received Caution With S98 none of the PW20i respond but all the PW20i load cells execute the command In the example given above all the PW20i on this bus are set to the baud rate 9600Bd whatever their previous settings Of course other baud rates can be set To do this set the required baud rate in the BDR command and modify the initialization of the master interface accordingly The baud rate is the transmission speed of the interface This does not change the number of measured values that the PW20i load cell takes per second A faster baud rate merely makes it possible to query a greater number of PW20i load cells per time unit in bus mode Baud rate Transmission time for one ASCII character With this information it is possible to estimate the transmission time for a command sequence To do this determine the number of characters in the command and multiply by the transmission time In addition to this the PW20i load cell has a Response time for each command These times can be found in the command descriptions total time transmission time Response time Operat
50. s POR IMD TRC MAV LIV Read set inputs outputs Select input mode Trigger setting Measured value trigger function Limit values PW20i Communication commands Operation with processor or terminal PW20i Communication commands 51 Port Set and Read Set and read digital inputs and outputs Response time lt 10 msec Parameter 4 Password protection no Parameter backup no The PW20i has a digital input which can be read using the POR command Input Query Effect Example HBM not intended POR Output of signal level at input The response contains four parameters The third value indicates the electrical status of the trigger input The fourth parameter has no significance for the PW20i The first two parameters can be used to read the limit value states LIV command Response to por is 0 1 1 x i e Limit value1 off Limit value2 on IN1 high Operation with processor or terminal 52 PW20i Communication commands Input Mode Set the function of the inputs Range 0 1 Factory setting 0 Response time lt 10 msec Parameter 1 Password protection no Parameter backup with TDD1 This command is used to select the function of the PW20i digital input Input IMD 0 IMD 1 Query Effect HBM IMD O 1 The logic state at the input can be queried with the POR command Any change in the level has no effect on the PW20i The input IN1 is set
51. sition In the binary output the sequence of the bytes can be selected as MSB LSB or LSB MSB With ASCII output the device address and or measurement status information can be output as well as the measured value Operation with processor or terminal PW20i Communication commands 15 Format binary Parameter Sequence for data output Measured value MSB before LSB LSB 0 no status Measured value MSB LSB Measured value LSB before MSB LSB 0 no status Measured value LSB MSB Measured value MSB before LSB LSB Status CRC Measured value LSB before MSB LSB Status CRC Format ASCII With ASCII output the separator of your choice is placed between the parameters see TEX command CRLF or the chosen separator follows the last parameter T separator number of characters 1st parameter 2nd parameter 3rd parameter End label Measured value 8 Address 2 CRLF or T Measured value 8 CRLF or T Identical to COF1 Identical to COF3 Measured value 8 Address 2 T 1 Status 3 CRLF or T Measured value 8 Status 3 CRLF or T Data output is related to the nominal value set for the PW20i see NOV command Output format Output on max load NOV gt 0 NOV 0 2 byte binary NOV value 20000 4 byte binary NOV value 5120000 ASCII NOV value 1000000 With the 2 Byte binary output the NOV value must be lt
52. standard filter Sampling rate 150 measurements s Device type 15 characters production number 7 characters program version Trigger input inactive User characteristic curve zero point 1000000 User characteristic curve end value 0 Obligation of verification deactivated 0 1000000 0 0 Linearization deactivated 0 0 0 0 Limit value 1 and 2 deactivated 0 Standstill monitoring off User scaling off Increment Gross measured value Tare memory cleared xxx 1 Standard meter starts with 0 172 Separators output in columns with crlf 0 0 0 0 0 Trigger function off all parameters 0 0 Zeroing on startup deactivated 0 1 any value Zero tracking deactivated The parameters marked with a are stored immediately on input EEPROM For these parameters TDD1 or TDD2 do not apply The commands CAL MSV MAV STP S and RES cannot be stored Query TDD Effect An output is not possible Operation with processor or terminal PW20i Communication commands 65 Command TDD 1 Effect With the following parameters the changed settings are stored first only in the working memory RAM i e not power failure protected Using the TDD1 command the settings changed in the working memory are saved power failure protected in the EEPROM ADR Address ASF Filter setting BDR Baud rate COF Configuration of data outp
53. tered directly or as an exponential representation e g 12000If or 1 2e4lf The exponent e can have 1 or 2 digits but must not be a number greater than 10 characters including the sign and the exponent Operation with processor or terminal PW20i Communication commands 7 Responses consist of ASCII characters and close with CRLF An exception to this is binary character output see MSV and COF commands Each command consists of the command shortform one or more parameters and the delimiter Input ABC X Y LF or Output ABC X Y LF or Example MSV 20 On this command 20 measured values will be output All ASCII characters lt 204 blank are allowed between the command shortform the parameters and the end label apart from 11H Ctrl q and 13H Ctrl s H Hexadecimal 2 2 Response to commands HBM Responses to inputs exception COF64 COF79 Response End label correct input 0 zero CRLF incorrect input CRLF Exceptions The commands RES STP S00 S99 do not bring a response The command BDR brings a response in the new baud rate The command ESR will identify the error Responds to output commands correct command Parameter1 Parameter n or measured values CRLF incorrect command CRLF error identification via ESR command Operation with processor or terminal PW20i Communication commands 2 3 Output types for measured values HBM You can choose two output
54. th the STP command Settings are made with the following inputs COF 128 e Make necessary settings e ICRi Set PW20i sampling rate e COF 128 The PW20i sends continuous measured values interval like ICR e STP Stop continuous sending e TDD1 Store protected against power failure e COF 128 The PW20i sends continuous measured values interval like ICR When power is connected the PW20i also starts data output without a separate prompt These output formats have another special feature depending on the trigger setting TRC command Trigger switched off continuous automatic data output Trigger switched on automatic data output only when a new measured value has been produced after triggering Output speed of measured values The maximum output rate of the PW20i is 600 measured values per second This data transfer rate also depends on the baud rate BDR the data output format the set mean value calculation ICR and the filter mode fmd 0 Operation with processor or terminal 18 PW20i Communication commands Table 1 shows the relationships with continuous data output MSV Measured value s ICR Time in ms Output format Requisite baud rates for MSV 0 BDR COF Binary format 2 9600 4800 2400 1200 1200 1200 characters with COF2 COF6 Binary format 4 characters with COF0 COF4 ASCII format measured value 10 characters with COF3 ASCII format measured value address 13 characters with
55. unit Any unit with a maximum of four characters can be entered If less than four characters are entered blanks are added to the input The unit entered is not appended to the measured value The characters must be entered in quotes Query ENU Effect Output of unit with 4 characters HBM Operation with processor or terminal 62 HBM PW20i Communication commands Identification Identification of transducer type and serial number Range 15 or 7 digits or numbers ASCII characters Factory setting dependent on transducer Response time Output lt 15 msec Input lt 180 msec Parameter 1 Password protection no Parameter backup with input Input Query Effect IDN lt Transducer type gt lt Serial number gt Enter the transducer type The transducer type and serial number are stored in the EEPROM of the transducer electronics The type name must have maximum 15 characters and must be entered as a string in quotes The serial number is set at the factory and must not be changed If less than 15 characters are entered for the type designation the input is automatically filled with blanks up to the maximum permitted number The manufacturer and the software version cannot be entered IDN An identification string is output 33 characters Sequence Manufacturer transducer type serial number software version e g HBM PW20i 0001 234 P62crif A fixed
56. using the command MSV ICRx av value determination using 2 measured values with x 0 7 where FMD 0 This results in the following setting options Filter mode fmd 0 o D Output rate Mw s 600 300 150 75 37 5 18 75 9 38 4 69 Nf D O B D N O HBM Operation with processor or terminal 42 PW20i Communication commands Filter mode fmd 1 Output rate Mw s asf4 asf5 The baud rate setting must be taken into consideration when setting the measurement data rate With high measurement data rates the baud rate setting must also be high to prevent loss of measurement data see COF command Query ICR Effect Output of set sampling rate 0 7 ka Note With ICR gt 1 this results in very good suppression of a possible interfering ee mains frequency of 50 Hz HBM Operation with processor or terminal PW20i Communication commands TAR HBM Tare Tare Range Factory setting Response time Parameter Password protection Parameter backup 43 with fmd0 lt 2 CR x 1 67msec 1 67 msec with fmd1 and asf0 lt 2 CR x 1 67msec 1 67 msec with fmd1 lt 2 CR x asf 1 9 1 67msec 1 67msec 0 no no data to back up The TAR command tares the current measured value After taring the system changes back to the net measured value TASO The current value is stored in the tare memory a
57. ut CSM Checksum in measurement status FMD Filter mode ICR Sampling rate IMD Function of inputs IN1 and IN2 LIV Limit value settings for limit values 1 and 2 MTD Standstill monitoring NOV User scaling TAS Gross net switch position TAV Tare memory contents TEX Output separator TRC Trigger function ZSE Zero on startup ZTR Automatic zero tracking HBM Operation with processor or terminal 66 HBM PW20i Communication commands Command TDD 2 Effect Transferring parameters from the EEPROM to the RAM The parameters listed under TDD1 are copied from the EEPROM to the RAM This happens automatically after Reset and power up Parameter backup without battery Storage of all settings such as filter limit frequency sampling rate baud rate Current User settings protected EEPROM User settings Factory setting Power failure protected storage Saving the setup parameters Operation with processor or terminal PW20i Communication commands 67 3 6 Error messages ESR Event Status Register Output of error messages Query ESR Effect This function delivers as defined by the IEC standard error messages as 3 digit decimal numbers The errors are linked by or Error message No error Not in use Device Dependent Error hardware error e g EEPROM error Execution Error error on parameter input Command Error command error command not available
58. without MAV command STP Stops automatic output ess Parameter settings possible COF3 deactivate automatic output TDD1 Power failure protected storage if required MSV or MAV Individual data output or individual trigger query if required Operation with processor or terminal PW20i Communication commands 55 Measured Alternative Value MAV Measured value trigger function Range Integer 32767 Long Integer 8388607 ASCII 21638399 Factory setting Overflow value Response time lt 25 msec Parameter Password protection no Parameter backup no data to back up Query MAV Effect If a new trigger measured value is calculated the measured value is output once only If no new measured value has yet been calculated the output value corresponds to the overflow value binary 800000h or ASCII 1638400 This value is also output after the measured value is read out and the query is repeated The measured value is output in ASCII format or binary format see COF command This command only returns measured values when the trigger function is activated see TRC command HBM Operation with processor or terminal 56 LIV HBM Limit Values PW20i Communication commands Limit value settings Range Factory setting Response time Parameter Password protection Parameter backup 1 2 0 1 0 2 0 1599999 0 1599999 1 0 0 0 0 for limit value 1 2 0 0 0 0 for limit value 2

Part 2: Communication commands Operating instructions

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