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User Manual - Test It Now

1. L RN Returns the complete set up of the instrument OPC Sets the Operation Complete bit in the Standard Event Status Register OPC Returns the Operation Complete status PRE lt nrf gt Set the Parallel Poll Enable Register to the value lt nrf gt PRE Returns the value in the Parallel Poll Enable Register RCL lt nrf gt Recalls a set up from store lt nrf gt 0 5 or 9 RST Resets the instrument SAM lt nrf gt Saves a set up in store lt nrf gt 0 5 SRE lt nrf gt Set the Service Request Enable Register to lt nrf gt SRE Returns the value of the Service Request Enable Register STB Returns the value of the Status Byte Register TST No self test capability returns O rmt WAI Wait for operation complete true Instrument Specific Commands RANGE lt nrf gt ADC AAC A10DC A10AC OHMS VAC VDC AUTO MAN LOZ HIZ FAST SLOW TREAD READ CANCEL NULL NULLOFF LIMITS lt nrf gt lt nrf gt LIMOFF COMP DB lt nrf gt DBOFF DEV lt nrf DEVOFF AXB lt nrf gt lt nrf gt AXBOFF MMON MMOFF MM HOLDON HOLDOFF LOGON lt nrf gt lt nrf gt lt nrf gt LOGOFF PAUSE LOG Sets the instrument range switches to non autoranging Selects mA DC measurement function Selects mA AC measurement function Selects 10A DC measurement function Selects 10A AC measurement function Selects Resistance Measurement function Selects Volts AC measurement function Selects Volts DC
2. 25 cycles 7096 and 250 cycles 096 Performance B C d EN61000 4 4 2004 Fast Transient 1kV peak AC line 0 5kV peak signal connections Performance B B e EN61000 4 5 2006 Surge 0 5kV line to line 1kV line to ground Performance A B f EN61000 4 6 2007 Conducted RF 3V 80 AM at 1kHz AC line only signal connections 3m therefore not tested Performance B A According to EN61326 1 the definitions of performance criteria are Performance criterion A During test normal performance within the specification limits Performance criterion B During test temporary degradation or loss of function or performance which is self recovering Performance criterion C During test temporary degradation or loss of function or performance which requires operator intervention or system reset occurs T Note The 1906 is a sensitive measuring instrument and if subjected to sufficiently large RF fields radiated or conducted measurements may deviate beyond the accuracy specification at certain frequencies up to 800MHz However possible deviations will be small and infrequent and are not deemed to be a problem in practice In all other respects the instrument will operate normally Performance A in fields up to 3V m Cautions To ensure continued compliance with the EMC directive observe the following precautions a Only use screened cables and connectors to connect between the multimeter s RS232 GPIB inte
3. is sent Returns the instrument identification The exact response is determined by the instrument configuration and is of the form lt NAME gt lt model gt 0 lt version gt lt rmt gt where NAME is the manufacturer s name lt MODEL gt defines the type of instrument and VERSION is the revision level of the software installed On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode IST Sequential command Operation complete message generated immediately after rmt is sent Returns ist local message as defined by IEEE Std 488 2 The syntax of the response is O rmt if the local message false or 1 lt rmt gt if the local message is true On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode LRN Sequential command Operation complete message generated immediately after rmt is sent Returns the complete set up of the instrument as a hexadecimal character data block approximately 1050 bytes long To re install the set up the block should be returned to the instrument exactly as it is received The syntax of the response is LRN lt Charater data gt lt rmt gt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode The settings in the instrument are not affected by execution of
4. LAD Listen Address must be followed by an address belonging to the required instrument 13H XOFF Stop transmission 14H TAD Talk Address must be followed by an address belonging to the required instrument 18H UDC Universal Device Clear GPIB INTERFACE When the GPIB interface is fitted the 24 way GPIB connector is located on the instrument rear panel The pin connections are as specified in IEEE Std 488 1 1987 and the instrument complies with IEEE Std 488 1 1987 and IEEE Std 488 2 1987 GPIB Subsets This instrument contains the following IEEE 488 1 subsets Source Handshake SH1 Acceptor Handshake AH1 Talker T6 Listener L4 Service Request SR1 Remote Local RL1 Parallel Poll PP1 Device Clear DC1 Device Trigger DT1 Controller CO Electrical Interface E2 GPIB IEEE Std 488 2 Error Handling 24 The IEEE 488 2 UNTERMINATED error addressed to talk with nothing to say is handled as follows If the instrument is addressed to talk and the response formatter is inactive and the input queue is empty then the UNTERMINATED error is generated This will cause the Query Error bit to be set in the Standard Event Status Register a value of 3 to be placed in the Query Error Register and the parser to be reset See the STATUS REPORTING CAPABILITIES section for further information The IEEE 488 2 INTERRUPTED error is handled as follows If the response formatter is waiting to send a response message and a PROGRAM MESSAGE TERMINATOR h
5. The display continues to show the same reading until a new non zero stable reading has been made at which point the display updates to the new reading This allows the probes to be removed from the signal being measured so that for instance the display can be examined if it could not be seen whilst probing the signal The display can be unfrozen by pressing the T HOLD key which will once again make the display follow the readings until the next stable reading The T HOLD mode operates with any of the post processing programs The T HOLD function can only be cancelled individually by holding the T HOLD key down for three seconds until CAnCEL d is displayed However PROG CANCEL will cancel T HOLD at the same time as all other programs Ax B Scaling Introduction To Ax B Scaling The Ax B program scales the measurement by the factor A and then offsets the result by B Factor A is a six digit number between 00000 and 999999 and offset B is a real quantity which depends on the meter function Separate values for A and B are stored for each meter function Factor A can take any value from 000000 to 999999 The range of possible B values is shown in table 2 Ax B scaling may also be applied before or after dB calculation and A calculations can be made on Ax B scaled measurements One set of values for A and B is kept for scaling after dB calculations regardless of the basic meter function By operating the appropriate program while Ax B scalin
6. 1 0 programmes the logger with automatic trigger every 1234 seconds into a circular store If no parameters are sent then the existing parameters are used If the lt nrf gt values sent with this command are not permissible values after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register Upon receipt of a TRG or GET if GPIB command the logger stores one reading Subsequent samples are recorded either at timed intervals if the triggering is automatic or upon receipt of each TRG or GET if GPIB if the triggering is external After receipt of the first TRG or GET if GPIB the LOG l e d flashes to indicate that the logger is active and the display stops showing ready The logger can be stopped in two ways either by issuing a PAUSE command or LOGOFF LOGOFF Sequential command Operation complete message generated immediately after execution Turn off and exit from the data logger If the logger was storing data then this will be stopped and the data retained for later retrieval or examination When the logger next stores data the old data will be overwritten If the data logger is not active then no action will be taken LOG Sequential command Operation complete message generated immediately after rmt is sent Returns the contents of the data logger 39 40 The syntax of the response is DATA LOGGER ASCII data gt lt rmt gt ASCII da
7. CONT l e d is lit whenever the continuity checker is turned on and the buzzer will sound when a low resistance is sensed The continuity checker is turned on or off via the BUZZER selections To access these selections first press PROG followed by BUZZER The display shows cont n if the continuity check is currently off or cont y if itis on To toggle the continuity checker between off and on press any key with a number beside it When the selection is made press ENTER to return to normal meter operation Note that having pressed PROG followed by BUZZER other buzzer selections are made available by repeated presses of the SCROLL key see ADVANCED FEATURES section Pressing ENTER saves all the buzzer selections made The continuity checker is available on all resistance ranges and senses when the voltage across the unknown is less than 50mV This represents approximately 609 on both the 200Q and 2kO ranges more on higher ranges Making Diode Checks Diode functionality checks can be made using the resistance ranges The recommended range is the 2kO range where the measurement current is just under 1mA Forward biased silicon junctions will produce an approximately mid scale reading This is achieved by connecting the anode to the red V O socket and the cathode to the black V Q A socket With the reverse connections a good silicon junction will give an OL reading 12 Advanced Features Parameter Values The advanced features include program
8. TRG command is received or GET if GPIB If the data logger is active the trigger is used by the logger instead and the reading response will not be triggered The syntax of the response is ASCII data gt lt rmt gt where ASCII data contains sixteen characters divided into two fields The first field of eleven characters contains the reading value and the second field of five characters contains the units if the reading is not in dBs or n nnnnnE n VDC n nnnnnE nMADC n nnnnnE tnKOHM nnn nnDB nnn nnn OVERLOAD OVERFLOW where n represents a decimal number The reading field may contain a fixed decimal point representaion of the reading with exponent in Volts mA or kOhms or a fixed decimal point number without exponent in dB or A or it may contain OVERLOAD or 4OVERFLOW The units field will contain VDC VAC MADC MAAC or KOHM depending on the meter function and readout value If the reading is in dB or A the units will be blank Examples 1 23456E 1 VDC 1 78912E 1MAAC 120 00DB On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode READ Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the next reading immediately after the command has been parsed The syntax of the response is the same as for TREAD described above On the serial interface the response
9. and read by the ESE command Bit7 Power On Set when power is first applied to the instrument Bit6 Not used Bit5 Command Error Set when a syntax type error is detected in a command from the bus The parser is reset and parsing continues at the next byte in the input stream Bit 4 Execution Error Set when an error is encountered while attempting to execute a completely parsed command The appropriate error number will be reported in the Execution Error Register as listed below 0 no error has occured 119 value out of range 121 attempted an illegal function change while a computation program is active 122 invalid store number or no valid data in store Bit3 Not used Bit2 Query Error Set when a query error occurs The appropriate error number will be reported in the Query Error Register as listed below 1 Interrupted error 2 Deadlock error 3 Unterminated error Bit1 Not used BitO Operation Complete Set in response to the OPC command Status Byte Register and Service Request Enable Register 26 These two registers are implemented as required by the IEEE std 488 2 Any bits set in the Status Byte Register which correspond to bits set in the Service Request Enable Register will cause the RQS MSS bit to be set in the Status Byte Register thus generating a Service Request on the bus The Status Byte Register is read either by the STB command which will return MSS in bit 6 or by a Serial Poll which will return
10. entry method is by scrolling through the possibilities using the RANGE A SCROLL and RANGE Y STEP EDIT keys Pressing ENTER when the required choice is displayed stores the value All parameter information is retained in battery backed memory so that the next time the parameter is edited the value that first appears when a program is invoked will be the last used value Separate values for the parameters used by A Ax B and LIMITS are retained for each meter function Overflow Indication The displayed result of measurement post processing is allowed to have values up to 999999 If the result is greater than 999999 then OFLO is displayed This differentiates between calculated overflows and hardware overload when the input signal is too large for the range and OL is displayed Function Cancellation Null All programs can be cancelled simultaneously by pressing PROG followed by CANCEL Individual programs can be cancelled by invoking the program and then pressing CANCEL before any parameter information is ENTERed e g the key sequence PROG dB CANCEL will cancel the dB program Note however that T HOLD which does not have any parameters can only be cancelled by holding the key down for three seconds until CAnCEL d is displayed NULL is toggled on and off by successive presses of the NULL key The NULL l e d is lit when the NULL feature is in operation Turning on NULL stores the currently displayed value which is then subtracted as a real
11. generated immediately after lt rmt gt is sent If the LIMITS program is currently operating then this command returns the result of the latest LIMITS Comparisons The syntax of the response is ASCII data gt lt rmt gt where ASCII data contains the the word HI LO PASS OVL OVL or LIMITS OFF HI indicates that the reading was greater than the upper set limit LO indicates that the reading was less than the lower set limit PASS indicates that the reading was between set limits or equal to one or both limits OVL and OVL indicate that the latest reading was in positive or negative overload respectively and that no comparison was made LIMITS OFF is returned if the LIMITS program is not currently operating On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode DB lt nrf gt Sequential command Operation complete message generated immediately after execution Start the dB readout mode using the optionally sent lt nrf gt reference value If no reference value is sent then the existing value is used If the lt nrf gt value sent with this command is not a permissible value after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register The permissible values for the dB reference are from 0 001 to 9 999 The units of the reference will depend on the ba
12. is sent immediately if in non addressable mode or when addressed to talk if in addressable mode CANCEL Sequential command Operation complete message generated immediately after execution Cancel simutaneously any of the following programs that are active AX B A dB MIN MAX LIMITS Update the display if T HOLD is active and the display is currently on hold but without quitting T HOLD NULL Sequential command Operation complete message generated immediately after execution Light the NULL l e d store the existing measurement as an absolute value and subtract it from all future measurements in this function until the NULLOFF command is received or the local NULL key is pressed The implications if computing programs are also active are the same as for manual operation see Advanced Features section If NULL is already active then no action will be taken Note that NULL cannot be activated while the AX B computation is active In this case an Execution Error is generated and error number 121 In Program is placed in the Execution Error Register 35 NULLOFF Sequential command Operation complete message generated immediately after execution Turn off the NULL LED and cancel operation of NULL If NULL is not currently active then no action will be taken Note that NULL cannot be cancelled while the Ax B computation is active In this case an Execution Error is generated and error number 121 In Program is placed i
13. measurement function Selects auto ranging Selects non autoranging function Selects 10MQ input impedance on 210mV and 2 1V DC ranges Selects 1GQ input impedance on 210mV and 2 1V DC ranges Set 575 digit mode Set 475 digit mode Return one triggered reading Return next reading Cancel all active computations and the data logger Store the NULL value and start NULL operating Stop NULL operating Start LIMITS program with optional new parameters Stop LIMITS program operating Return the current result of the LIMITS comparison Start dB computations with optional new parameters Stop the dB computations Start the A computations with optional new parameters Stop the A computations Start measurement scaling with optional new scaling parameters Stop measurement scaling Set MIN value MAX value latest reading and start recording MIN MAX values Stop MIN MAX recording retain latest MIN MAX values for retrieval by MM Return the latest MIN and MAX values Start T HOLD readout mode or unfreeze display if currently held Exit from T HOLD mode Enter the data logger with optional new parameters Stop logging readings and exit the data logger Stop logging readings but do not exit the data logger Return the Data Logger contents 43 Instrument Specific Commands continued FILTER lt nrf gt Set the digital filter to values indicated by the code lt nrf gt TRGSET lt nrf gt Set the type of reading trigger to filtered or immediate BU
14. peak any range DC Amps Range Accuracy Voltage Burden Max Input 200pA 0 08 12d 2mA 0 08 12d 300 mV max 1A 300V 20mA 0 0896 12d fuse protected 200mA 0 08 12d 10A up to 2000mA 0 08 12d 650mV max 10A 300V 10A above 2000mA 0 12 12d fuse protected AC AMPS True RMS Range Accuracy Voltage Burden Max Input 45 Hz 1 kHz 200pA 0 37 100d 2mA 0 37 100d 300mV max 1A 300V 20mA 0 37 100d fuse protected 200mA 0 37 100d 10A up to 2000mA 0 37 100d 650mV max 10A 300V 10A above 2000mA 0 496 100d fuse protected Accuracy specifications apply for readings between 10 and 100 of full scale Additional error at crest factor 3 typically 0 796 Display Display Type Scale Length Reading Rate 4 4 digit 5 4 digit Overrange Indication Overflow Indication Annunciators Input Current DC NMR Input Characteristics 1k Unbalanced CMR Hi Z Null Digital Filter Computing Functions T HOLD Touch amp Hold 96 DEV dB Ax B Limits Min Max Data Logger 13mm LED 8 digit Selectable 5 digit or 475 digit 5 readings sec All functions except Ohms 1 4 readings sec Ohms 3 5 readings sec DC and AC current 3 5 readings sec AC volts 3 readings sec DC volts 1 reading sec Ohms Displays OL if input too great for range Displays OFLO if calculat
15. regardless of the meter range If the measurement result is less than the lower limitan L is shown in the right most character of the display Similarly if the measurement result is between the limits a P is shown and if it s above the higher limitan H is shown Separate limit values are retained for all basic meter functions By entering the LIMITS program while the dB or A program is running comparisons may also be performed with dB or A96 results Separate limit values are retained for dB and A result comparisons As an aid for go no go testing the buzzer may be programmed to sound either if the result falls within the limits or outside the limits The LIMITS program is called up by pressing PROG followed by LIMITS Upon entry to the program the lower limit is displayed for editing if required The limits are floating point numbers and are edited as described in the Parameter Values section When A limits are displayed the units are percent dB limits are in dBs but all other limit value units are indicated by the units l e d s to the right of the display Pressing ENTER stores the lower limit and causes the upper limit top be displayed for editing Pressing ENTER again stores the upper limit and starts the comparisons LIMITS comparison may be individually cancelled by pressing CANCEL at any time while the either limit is shown Alternatively the program may be cancelled by pressing PROG and then holding down the LIMITS key for 3 seconds
16. see Parameter Values section or the program may be individually cancelled by pressing CANCEL The program starts operating when ENTER is pressed A calculates the difference between the latest measured value and the reference value and displays this as a percentage of the reference The readout is shown to be in percent by the lighting of the A l e d No units l e d s are lit to the right of the display 15 Using A with other programs NULL and or Ax B may be operated before or during operation of A The A calculations are always performed after the measurement has been NULLed and or scaled by Ax B Note however that NULLing cannot be invoked after Ax B A results can be stored in the data logger by invoking the logger while A is running The logged results will be lost if A is cancelled A results can be compared with A limits by running the LIMITS program while the A program is running A set of high and low limit values is reserved for A comparison As with normal limits testing a P H or Lis displayed on the right most digit to indicate the result of the comparison Maximum and minimum A measurements can be recorded by starting the recording while the A program is running T HOLD display is possible while running A Storing and Recalling Setups Six non volatile stores are available for storing complete instrument setups including all parameters used by the post processing programs To save the present instrument se
17. than 0 or greater than 255 an execution error is generated and error number 119 Value out of range is placed in the Execution Error Register SRE Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value of the Service Request Enable Register in lt nr1 gt numeric format The syntax of the response is lt nr1 gt lt rmt gt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode Example If the Service Request Enable Register contains 01000001b the response to SRE will be 65 lt rmt gt 31 STB Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value of the Status Byte Register in lt nr1 gt numeric format The syntax of the response is nr1 rmt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode Example If the Status Byte Register contains 01000001b the response to STB will be 65 lt rmt gt TRG Sequential command Operation complete message generated immediately after execution Performs one of two possible trigger functions If the data logger is active and in the ready condition then TRG causes the logger to start recording readings and triggers the first sample If the logger trigger is set to automatic then subsequent read
18. the LRN command OPC Sequential command Operation complete message generated immediately after execution Sets the Operation Complete bit bit 0 in the Standard Event Status Register This will happen immediately the command is executed because of the sequential nature of all operations OPC Sequential command Operation complete message generated immediately after lt rmt gt is sent Query operation complete status The syntax of the response is 1 lt rmt gt The response will be available immediately the command is executed because of the sequential nature of all operations On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode PRE lt nrf gt Sequential command Operation complete message generated immediately after execution Set the Parallel Poll Enable Register to the value lt nrf gt If the value of lt nrf gt after rounding is less than 0 or greater than 255 an execution error is generated and error number 119 Value out of range is placed in the Execution Error Register PRE Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value in the Parallel Poll Enable Register in lt nr1 gt numeric format The syntax of the response is lt nr1 gt lt rmt gt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in a
19. the logger is active or MIN MAX is recording then Function Change commands are prohibited In this case an Execution Error is generated and error number 121 In Program is placed in the Execution Error Register RANGE lt nrf gt Sequential command Operation complete message generated immediately after execution Sets the meter range to code lt nrf gt depending on meter function as specified below in table 4 Range lt nrf gt Volts Current Resistance 0 210mV 210pA 2100 EH SEEN E e T 5 21MQ Table 4 Remote Range Setting Codes If the value of lt nrf gt after rounding is outside the range specified for the meter function in Table 4 an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register If the meter function is set to 10Amps then this command performs no action an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register This command places the meter in the non autoranging mode ADC Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to mA DC with the range set to the range last used in this function AAC Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to mAAC with the range s
20. until CAnCEL d is displayed MIN MAX Storage The MIN MAX program records the maximum and minimum readout values from the time the program is started until the time when the values are examined It is possible to trace the minima and maxima of basic measurements or the results of all post processing calculations The storage of MIN MAX is started by pressing PROG followed by MIN MAX The MIN MAX l e d lights to show that the program is active Once the program is active pressing PROG followed by MIN MAX again halts it and allows the recorded values to be examined The first value to be displayed is the minimum value indicated by Lo being briefly displayed before the actual value Pressing MIN MAX a second time displays Hi followed by the maximum value Having examined the recorded minimum and maximum there are two ways to continue recording If ENTER is pressed the display returns to the previous readout mode and the recording of max and min starts again the existing min and max values are lost Alternatively if MIN MAX is pressed a third time instead of ENTER then the display returns to its previous mode and recording continues with the existing min and max values in place MIN MAX may be cancelled individually by pressing CANCEL at any time during examination of the recorded min or max values If MIN MAX is operating but the data is not presently being examined then it can be cancelled either by pressing PROG MIN MAX CANCEL or by pressing P
21. EVER CLEAN WITH SOLVENTS TEST EQUIPMENT RISK ASSESSMENT Recommendation from the U K Health and Safety Executive Users of this equipment and or their employers are reminded that Health and Safety Legislation require them to carry out valid risk assessments of all electrical work so as to identify potential sources of electrical danger and risk of electrical injury such as from inadvertent short circuits Where the assessment show that the risk is significant then the use of fused test leads constructed in accordance with the HSE guidance note GS38 Electrical Test Equipment for use by electricians should be used TITiz Thurlby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England Telephone 44 0 1480 412451 Fax 44 0 1480 450409 e mail sales tti test com International website www tti test com UK website www tti co uk Book Part No 48581 1070 Issue 7
22. Error Register 0 Query Error Register 0 x X Parallel Poll Enable Register 0 Registers marked thus are specific to the GPIB section of the instrument and are of limited use in an ARC environment The instrument will be in local state with the keyboard active 25 Due to the non volatile storage the power on settings are essentially modified by any command local or remote which changes any value not listed above If a defined state is required at start up by the controller the RST command should be issued which will load the settings as listed in the description of that command If for any reason an error is detected at power up in the non volatile ram a warning will be issued and all settings will be returned to their default states as for a RST command STATUS REPORTING This section describes the complete status model of the instrument Note that some registers are specific to the GPIB section of the instrument and are of limited use in an ARC environment Standard Event Status and Standard Event Status Enable Registers These two registers are implemented as required by the IEEE std 488 2 Any bits set in the Standard Event Status Register which correspond to bits set in the Standard Event Status Enable Register will cause the ESB bit to be set in the Status Byte Register The Standard Event Status Register is read and cleared by the ESR command The Standard Event Status Enable register is set by the ESE lt nrf gt command
23. MESSAGE TERMINATOR A RESPONSE MESSAGE TERMINATOR is the carriage return character followed by the new line character ODH OAH Each query produces a specific RESPONSE MESSAGE which is listed along with the command in the REMOTE COMMANDS section WHITE SPACE is ignored except in command identifiers e g C LS is not equivalent to CLS WHITE SPACE is defined as character codes 00H to 20H inclusive with the exception of the codes specified as ARC interface commands The high bit of all characters is ignored The commands are case insensitive GPIB REMOTE COMMAND FORMATS 28 The GPIB interface has an effective input queue length which is variable between about 156 and 210 characters This is because GPIB input is internally converted to serial data and sent to the instrument s main processor via the ARC serial interface The ARC interface will send XOFF when approximately 200 characters are in the queue XON will be sent when approximately 100 free spaces become available in the queue after XOFF was sent The queue contains raw un parsed data which is taken by the parser as required Commands and queries are executed in order and the parser will not start a new command until any previous command or query is complete There is no output queue which means that the response formatter will wait indefinitely if necessary until the instrument is addressed to talk and the complete response message has been sent bef
24. RE key is pressed when operating from the keyboard The L C field is edited in the same way as the E A field The field should be toggled to L for a linear store or C for a circular store NNNN E A C L Time Interval for External or Circular or Auto Triggered Auto Triggered Linear store Samples Samples Fig 4 Data Logger Parameters Once the parameters are set pressing ENTER stores the parameters and arms the logger In this state no samples are stored but ready flashes onto the display every few seconds The logger becomes active and the LOG l e d flashes when LOG is pressed Samples are now stored at each trigger automatic or external until LOG is again pressed to stop the logger When the logger is stopped the parameters are again displayed and the stored data may be examined by pressing the SCROLL key If the logger contains no data then no dAtA is displayed briefly before returning to the parameter edit display If there is stored data then the last location is displayed first The store location is displayed briefly before the data itself The right most character on the display contains r to show that this is a store readout and not a live measurement To move forward through the store press SCROLL and to move backward through the store press STEP EDIT The readout location wraps round from the last location to the first in the forward direction and vice versa in the backward direction If the SCROLL key or STEP EDIT key is held
25. ROG and then holding down MIN MAX until CAnCEL d is displayed 19 20 Error Messsages If the power up self test of the EEPROM fails Error 1 is displayed and a warning buzzer sounds The meter cannot be used under these circumstances and further operation is inhibited until the instrument has been recalibrated For operation within the published specification an accurate meter recalibration is required However if the user wishes to get the meter working for less accurate work or for further diagnostic checks the meter can be calibrated with default calibration constants To program in default calibration constants switch off the instrument and with a thin blunt implement push in the recessed CAL switch located at the top left corner of the front panel until it latches in Switch on again the CAL l e d next to the CAL switch should light and dEF CAL will be shown on the main display Press the STORE button on the keyboard below the main display CAL donE will be displayed Press in the CAL switch to release it and normal meter operation should commence with default calibration If the self test finds corrupted data in the battery backed RAM then the meter bleeps and Error 2 is displayed for a few seconds while default instrument settings are loaded The meter should then commence normal operation but all functions and parameters will have been reset to the default condition The calibration constants are not affected by this operation An Er
26. RQS in bit 6 The Service Request Enable register is set by the SRE lt nrf gt command and read by the SRE command Bit 7 Not used Bit6 RQS MSS This bit as defined by IEEE Std 488 2 contains both the Requesting Service message and the Master Status Summary message RQS is returned in response to a Serial Poll and MSS is returned in response to the STB command Bitb ESB The Event Status Bit This bit is set if any bits set in the Standard Event Status Register correspond to bits set in the Standard Event Status Enable Register Bit4 MAV The Message Available Bit This will be set when the instrument has a response message formatted and ready to send to the controller The bit will be cleared after the Response Message Terminator has been sent Bit 3 Not used Bit 2 Not used Bit 1 Not used Bit O Not used POWER ON COMMAND ERROR EXECUTION ERROR ERROR NUMBER IN EXECUTION ERROR REGISTER EER READ AND CLEAR QUERY ERROR ERROR NUMBER IN QUERY ERROR REGISTER QER READ AND CLEAR OPERATION COMPLETE Y STANDARD EVENT STATUS REGISTER ESR READ AND CLEAR STANDARD EVENT STATUS ENABLE REGISTER ESE lt NRF gt SET TO lt NRF gt ESE READ STATUS BYTE REGISTER SERIAL POLL READ WITH RGS STB READ WITH MSS SERVICE REQUEST ENABLE REGISTER SRE lt NRF gt SET TO lt NRF gt SRE READ Status Model ARC REMOTE COMMAND FORMATS Serial input to the instrum
27. THURLBY THANDAR INSTRUMENTS Model 1906 COMPUTING MULTIMETER INSTRUCTION MANUAL Introduction Specification Safety EMC Installation Introduction to Front Panel Making Basic Measurements Advanced Features Error Messsages Default Instrument Settings Remote Operation Remote Commands Maintenance and Repair Table of Contents Co N OO N gt 10 13 20 20 21 29 44 Introduction This instrument is a mains operated high performance autoranging multimeter providing 575 digit resolution 210000 counts switchable to 4 digits 21000 counts for a higher reading rate It has a 7 segment l e d display coupled with l e d annunciators for displayed units and instrument status The main features are ARC serial interface as standard GPIB optional True RMS AC measurements e Four terminal Ohms Selectable audible continuity checker T Hold mode holds onto a stable reading until updated Display nulling a different value can be set up for each function 100 point data logger circular or linear store Measurement post processing percentage deviation from a user entered reference decibel calculations linear scaling with offset limits comparison for go no go testing automatic storage of minimum and maximum readings Selectable digital filter Programmable buzzer Battery backed RAM storage of six instrument set ups automatic power up with last used settings retention of
28. ZZ lt nrf gt lt nrf gt lt nrf gt Program buzzer activity to the codes lt nrf gt lt nrf gt lt nrf gt LRN lt character data gt Send instrument set up information to the multimeter STEPCAL Used in calibration only refer to service manual SETCAL lt nrf gt Used in calibration only refer to service manual EER Returns the value in the Execution Error Register QER Returns the value in the Query Error Register Maintenance and Repair The Manufacturers or their agents overseas will provide repair for any unit developing a fault Where owners wish to undertake their own maintenance work this should only be done by skilled personnel in conjunction with the service manual which may be purchased directly from the Manufacturers or their agents overseas Calibration The Manufacturers will provide a re calibration service as will their agents overseas Where owners wish to carry out re calibration themselves this should only be done by skilled personnel with access to precision equipment working in conjunction with the service manual which may be purchased directly from the Manufacturers or their agents overseas Cleaning 44 If the instrument requires cleaning use a cloth that is only lightly dampened with water or a mild detergent Polish the display window with a soft dry cloth WARNING TO AVOID ELECTRIC SHOCK OR DAMAGE TO THE INSTRUMENT NEVER ALLOW WATER TO GET INSIDE THE CASE TO AVOID DAMAGE TO THE CASE OR DISPLAY WINDOW N
29. _J 4 1 o i x OWER CANCEL NO A dB FILTER BUZZER AUTO SCROLL 10A B i 0 1 Fused Use Tes Local G a AC 5 a ee d T 6 rane ENTER RANGE All inputs kV peek to ME EC D 0 urs ADDR BAD Ae8 LIMITS Min Max RECALL STEP EDIT POWER SWITCH REMOTE CONTROL BASIC METER FUNCTIONS RANGE SWITCHES Fig 1 Front Panel Layout Making Basic Measurements General If basic measurements are required with no post processing of the results all programs currently operating can be cancelled by pressing PROG followed by CANCEL Note that the l e d above the PROG key lights to show that the next key press will invoke the function specified under that key in blue Scale Length The scale length may be 210000 57 digits for high accuracy or 21000 475 digits if the higher measurement rate is required The selection is made by pressing the PROG key twice Function Selection Voltage current and resistance measurement functions are selected by pressing the appropriate V mA 10A or Q key For voltage and current measurements ac or dc is selected by pressing either the AC or DC key The l e d s above these switches indicate the currently selected function Note that when some post processing programs are running function changes are inhibited this is indicated by In Pro being displayed All programs can be cancelled simultaneously by pressing PROG followed by CANCEL or programs can be selectively ca
30. as been read by the parser or the input queue contains more than one END message then the instrument has been INTERRUPTED and an error is generated This will cause the Query Error bit to be set in the Standard Event Status Register a value of 1 to be placed in the Query Error Register and the response formatter to be reset thus clearing the output queue The parser will then start parsing the next PROGRAM MESSAGE UNIT from the input queue See the STATUS REPORTING CAPABILITIES section for further information The IEEE 488 2 DEADLOCK error is handled as follows If the response formatter is waiting to send a response message and the input queue becomes full then the instrument enters the DEADLOCK state and an error is generated This will cause the Query Error bit to be set in the Standard Event Status Register a value of 2 to be placed in the Query Error Register and the response formatter to be reset thus clearing the output queue The parser will then start parsing the next lt PROGRAM MESSAGE UNIT gt from the input queue See the STATUS REPORTING CAPABILITIES section for further information GPIB Parallel Poll Complete parallel poll capabilities are offered on this multimeter The Parallel Poll Enable Register is set to specify which bits in the Status Byte Register are to be used to form the ist local message The Parallel Poll Enable Register is set by the PRE lt nrf gt command and read by the PRE command The value in the Parallel Pol
31. be input manually from the keyboard by pressing STORE once logging has been started or remotely via ARC or GPIB see the appropriate remote control section Setting Up and Running the Data Logger 16 The data logger is invoked by pressing the LOG key Upon entering the logger the first display shows all the existing logger parameters which may at this point be changed if required Pressing CANCEL will exit from the logger From this display the logger may also be armed using ENTER or logged data may be examined by pressing SCROLL see Operational Flowchart Fig 5 The parameters for the logger and their format are shown below in Fig 4 There is one flashing edit cursor which can be moved through the fields by pressing the STEP EDIT key The time interval for the automatic sampling is displayed in seconds and is the time between auto triggered samples when the E A field is setto A The time interval is edited by direct entry from the numeric keys at the flashing edit point Note that STEP EDIT steps the edit point through the other two fields before wrapping round from right to left Every measurement is stored when the time interval is set to 0000 and E A is setto A The E A field is edited by moving the edit cursor to it using the STEP EDIT key Once the field is flashing its value can toggled between E and A by pressing any numeric key When the E A field is setto E the time interval is disregarded and samples are triggered every time the STO
32. buzzer O off 1 0n Parameter 2 limits comparison buzzer 0 off 1 sound if inside limits 2 7 sound if outside limits Parameter 3 data logger trigger buzzer O off 1 on Example BUZZ 1 1 0 programmes the buzzer to give continuity indication on resistance measurements to sound if the LIMITS program is active and readings are within limits and to give no audible indication if a trigger occurs when the data logger is active If the lt nrf gt values sent with this command are not permissible values after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register LRN character data Sequential command Operation complete message generated immediately after execution Re configure the multimenter according to the instrument set up information contained in character data The set up information must previously have been obtained using the LRN query Note that the response to LRN includes the LRN command mnemonic so it is only necessary to send this response in full to re configure the instrument The instrument looks for H at the beginning of the data and checks for the correct number of bytes If either is found to be wrong then a command error is reported in the Standard Event Status Register STEPCAL Sequential command Operation complete message generated immediately after execution Used for meter calibration only refer to service man
33. ddressable mode Example If the Parallel Poll Enable Register contains 01000001b the response to PRE will be 65 lt rmt gt RCL lt nrf gt Sequential command Operation complete message generated immediately after execution Recalls the instrument set up contained in store number lt nrf gt Valid store numbers are 0 5 and 9 Recalling store 9 sets all parameters to the default settings see DEFAULT INSTRUMENT SETTINGS If the value of lt nrf gt after rounding is invalid or no set up has been saved in the specified store then an execution error is generated and error number 122 Invalid Store is placed in the Execution Error Register RST Sequential command Operation complete message generated immediately after execution Resets the instrument parameters to their default values see DEFAULT INSTRUMENT SETTINGS No other action is taken SAV lt nrf gt Sequential command Operation complete message generated immediately after execution Saves the complete instument set up in the store number lt nrf gt Valid store numbers are 0 5 If the value of lt nrf gt after rounding is invalid then an execution error is generated and error number 122 Invalid Store is placed in the Execution Error Register SRE lt nrf gt Sequential command Operation complete message generated immediately after execution Set the Service Request Enable Register to lt nrf gt If the value of lt nrf gt after rounding is less
34. different types of measurements Making Voltage Measurements Voltage measurements are made using the red V Q and the black V Q A sockets having selected the required voltage function as explained above The V Q A socket is connected to analogue common inside the meter and for DC measurements the red socket which is also marked HI is the positive input 10 Making Current Measurements Current measurements up to 200mA are made using the mA and V Q A sockets the mA socket is the positive input Current measurements up to 10A are made using the 10A and V Q A sockets the 10A socket is the positive input The 10A range is treated as a separate function from the other current ranges and autoranging does not extend from the 200mA range to the 10A range Current Range Protection The mA input socket is protected by a fuse which is mounted on the instrument s rear panel This provides protection for the 200A 2mA 20mA and 200mA ranges The 10A input is protected by a fuse mounted inside the instrument on the main PCB see Fig 2 To replace this fuse the top cover must be removed 1 Disconnect the instrument from all voltage sources 2 Unclip the front bezel by gently pulling the centre of each long edge up and forward The case halves are held together by 4 plastic push rivets Use the blade of a small screwdriver in the slot beside each rivet to first ease out the rivet head and then fully remove the rivet body Separate the case halv
35. ding during which time the result of a MM query will be the INVALID message MMOFF Sequential command Operation complete message generated immediately after execution Stop recording MIN MAX values and exit from MIN MAX recording mode The recorded MIN MAX values will remain unchanged and can be read using the MM command until the meter function is changed or MIN MAX is restarted which will cause the values to become invalid If MIN MAX is not active then no action will be taken MM Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the recorded MIN and MAX values The syntax of the response is MIN MAX ASCII data rmt ASCII data contains two fields separated by a space units data where the units field contains the units of the basic meter function and data is the formatted data field The basic meter function units are VOLTS DC VOLTS AC MILLIAMPS DC MILLIAMPS AC KOHMS This field is fourteen characters wide between the dash and separating space The data field contains the MIN value followed by the MAX value separated by a comma Each value is contained in eleven characters tn nnnnnE tn tnnn nnDB tnnn nnn zOVERLOAD zOVERFLOW Examples 0 12345E 1 0 56789E 2 20 00DB 100 00DB If there are no valid MIN MAX values then the response syntax is MIN MAX INVALID On the serial interface the response is sent immediately if in non addressab
36. dit mode is to toggle on or off the continuity checker The display shows cont and the state of the continuity checker y ifit sonand n if it s off The state of the checker is toggled by pressing any numeric key Pressing SCROLL moves to the limits comparison selection The display shows HIL and the current state of OFF in orout The buzzer may be programmed to sound if the current measurement is within programmed limits in outside the limits out or neither OFF Pressing any numeric key rolls round the three possibilities Pressing SCROLL again moves to the data logger trigger indicator selection The display shows trIGand y or n which are toggled by pressing any numeric key If y the buzzer will sound each time a trigger initiates storage of a measurement in the data logger if n then no indication is given When all necessary choices are made pressing the ENTER key stores the new programming Pressing CANCEL exits the buzzer programming mode leaving all parameters unchanged The multimeter incorporates a digital filter which averages results over a number of readings The number of readings n partly determines the response time to a stable reading Increasing n will improve noise rejection but increase settling time In order to follow large signal changes quickly however the filter will abandon the existing average if the reading changes by more than a jump out value j The averaging process then starts again averaging over successive read
37. down the readout point steps rapidly through the store displaying only the locations until the key is released PRESS LOG START PROGRAM ES Y d DISPLAY EDIT PARAMETERS v CANCEL SCROLL ENTER v EXAMINE STORED DATA STARTING AT LAST STORED LOCATION RECORD DATA LOG 4 SCROLL STEP EDIT ENTER READY LOG p START I OG p_ STOP TO GO RECORDING RECORDING SCROLL SCROLL FORWARD BACKWARDS THROUGH THROUGH DATA DATA CANCEL Fig 5 Operational Flow Chart of the Data Logger 17 If data storage is stopped and then restarted without exiting the data logger then storage continues from the next store location without overwriting the old data To restart the logger from location 0 it is necessary to cancel the logger first and then re enter The old data may again be examined but it will be overwritten when storage is started again Note that in addition to cancelling the logger by means of the CANCEL key holding the LOG key down at any time for three seconds until CAnCEL d appears on the display will also cancel the logger Operation of the data logger is presented in flow chart form in Fig 5 T Hold The touch and hold mode is entered by pressing T HOLD When in this mode the T HOLD l e d is lit When first switched into this mode the display is continually updated until a stable reading is reached at which point the display freezes
38. e conductor The mains plug must be inserted before connections are made to circuits being measured Power On The power switch is located bottom left of the front panel At power up the meter displays the installed software revision whilst performing self tests on the internal RAM and the EEPROM containing the calibration constants At the end of these tests the meter will commence normal operation with all parameters set as they were at last switch off If the self test fails the buzzer sounds and one of two error messages Error lor Error 2 willbe displayed see the Error Message section Introduction to Front Panel The main display consists of eight 7 segment characters with decimal points which are used to give up to six digits of numerical information plus polarity indication Displayed units are indicated by the top three l e d s to the right of the digits except when making dB or A readings The main display also gives prompts error messages and instrument status Below the displayed units l e d s is the CONTINUITY indicator which lights when the audible continuity tester is active To the left of the main display at the top is the recessed CAL enable switch with its indicator which lights when the meter is in its calibration mode Below the CAL l e d are three computation indicators which light to show which computations are active The keyboard consists of momentary switches each with more than one function Colour coding sho
39. e sections for GPIB and ARC It is therefore only necessary to read the general sections and those sections specific to the interface of interest ADDRESS AND BAUD RATE SELECTION For successful operation each instrument connected to the ARC or GPIB must be assigned a unique address and in the case of ARC all must be set to the same baud rate The instrument s remote address for operation on both the ARC and GPIB interfaces is set via the keyboard by pressing PROG followed by ADDR The display shows Addr nn where nn is the address from 0 30 The address is set by scrolling The SCROLL key scrolls up and the STEP EDIT key scrolls down Once the required address is shown it is stored by pressing ENTER Pressing CANCEL will exit back to normal operation leaving the address unchanged The RS232 Baud rate is set by pressing PROG followed by BAUD There are three possibilities which are scrolled through using SCROLL or STEP EDIT The selection is stored by pressing ENTER Pressing CANCEL will exit back to normal operation leaving the Baud rate unchanged When operating on the GPIB all device operations are performed through a single primary address no secondary addressing is used NOTE GPIB address 31 is not allowed by the IEEE 488 standards and it is not possible to select it even as an ARC address REMOTE LOCAL OPERATION At power on the instrument will be in the local state with the REMOTE led off In this state all keyboard operati
40. ed result too large for display L e d annunciators for range function and program modes 100 pA gt 60dB at 50 60Hz gt 120dB at DC 50Hz 60Hz DC ranges gt 60dB at DC 50Hz 60Hz AC ranges Switchable high impedance gt 1GQ on 200mV and 2V DC ranges Operates over full range values can be stored for every function 10 options including optimised default values for each range and function Reading is held when stable Displays deviation from entered reference value Displays measurement in dB relative to 1V 1mA 1kQ or user entered value or in dBm Linear scaling of results with offset Reading displayed with H L or P pass with respect to user defined high and low limits Minimum and maximum reading stored Manual or automatic storage of 100 measurements Interfaces RS232 GPIB Optional Power Requirements AC Input Power Consumption General Operating Range Storage Range Environmental Size Weight Safety EMC Baud rates 300 1200 or 9600 Complies fully with the ARC Addressable RS232 Chain interface standard Address selectable from the front panel Fully complies with IEEE 488 2 220V 240V or 110V 120V AC 10 50 60Hz by rear panel adjustment Installation Cagetory Il 25VA max 5 C to 40 C 20 to 80 RH 40 C to 60 C Indoor use at altitudes up to 2000m Pollution Degree 1 260 W x 88 H x 235 D mm excluding handle and feet 2 2kg Comp
41. ent is buffered in a 256 byte input queue which is filled under interrupt in a manner transparent to all other instrument operations The instrument will send XOFF when approximately 200 characters are in the queue XON will be sent when approximately 100 free spaces become available in the queue after XOFF was sent This queue contains raw un parsed data which is taken by the parser as required Commands and queries are executed in order and the parser will not start a new command until any previous command or query is complete There is no output queue which means that the response formatter will wait indefinitely if necessary until the instrument is addressed to talk and the complete response message has been sent before the parser is allowed to start the next command in the input queue Commands are sent as PROGRAM MESSAGES by the controller each message consists of zero or more PROGRAM MESSAGE UNIT elements separated by PROGRAM MESSAGE UNIT SEPARATOR gt elements PROGRAM MESSAGES are separated by PROGRAM MESSAGE TERMINATOR elements which consist of the new line character OAH A PROGRAM MESSAGE UNIT SEPARATOR is the semi colon character 3BH 27 A PROGRAM MESSAGE UNIT is any of the commands in the REMOTE COMMANDS section Responses from the instrument to the controller are sent as RESPONSE MESSAGES A RESPONSE MESSAGE consists of one RESPONSE MESSAGE UNIT followed by a RESPONSE
42. es Visit www tti test com for further details 3 Replace the fuse with one of an identical rating using the diagram below as a guide Reassemble in the reverse order The current range protection fuse ratings are mA input rear panel 20mm 1A F HBC 10A input inside case 20mm 10A F HBC Rear Panel 10 A range Protection fuse Front Panel Fig 2 Location of 10A Range Fuse 11 Making Resistance Measurements and Continuity Checks Resistance measurements may be made using either a two terminal or a four terminal method The four terminal method overcomes inaccuracies due to test lead resistance by sensing the voltage across the unknown resistance via the separate HI and LO SENSE inputs If the sense inputs are not connected externally the measurement becomes two terminal the voltage sensing being performed internally at the V Q and V O A inputs The connections for four and two terminal measurements are shown in Fig 3 For correct four terminal operation the proper lead polarity must be maintained A A Hi O SENSE O C je ey A SENSE p H X 1000V 760 Vrms 750Vrms Mex Nex bns ed 2 O SENSE ae OQ SENSE V O A 10A mA Ee n Fused Fused All inputs 1KV pea All inputs 1kV peak to ARC GPIB ARC GPIB 2 Terminal 4 Terminal Fig 3 Resistance Measurement Connections The
43. et to the range last used in this function A10DC Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to 10A DC A10AC Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to 10A AC 33 34 OHMS Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to resistance measurement with the range set to the range last used in this function VAC Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to Volts AC with the range set to the range last used in this function VDC Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the meter function to Volts DC with the range set to the range last used in this function AUTO Sequential command Operation complete message generated immediately after execution Set the meter to Autoranging If the meter is set to 10A no action is taken MAN Sequential command Operation complete message generated immediately after execution Set the meter to manual ie non autoranging with the meter set to the present ran
44. g is in operation Ax B scaled readings can be stored in the data logger compared with set limits using the LIMITS program or minimum and maximum values can be traced using the MIN MAX program Meter Function B Voltage 000 000mV 9999 99V Current to 200mA 000 000pA 999 999mA Current to 10A 000 000pA 99 9999A Resistance 000 0002 99 9999MQ Table 2 Permissible B Values Used in Ax B 18 Setting Up and Operating Ax B The Ax B program is invoked by pressing PROG followed by Ax B The program first displays the existing value of A This is a floating point number and may if required be edited as described in the Parameter Values section Pressing ENTER will store the A value and the existing B value will be displayed for editing Again this number is edited as a floating point number but note that it will have units which in the case of Ax B scaling of dB readouts will be in dBs Pressing ENTER stores the B value and starts the Ax B program operating The Ax B program may be individually cancelled by pressing CANCEL at any time while the parameters are displayed Alternatively the program may be cancelled by pressing PROG and then holding down the Ax B key for 3 seconds until CAnCEL d is displayed Limits Comparison The LIMITS program compares the measurement results with user specified high and low limit values The limit values are stored as absolute quantities and the comparisons can be made
45. ge If the meter is set to 10A then no action is taken LOZ Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the Volts DC function to low input impedance 10M on all ranges If the meter is presently set to Volts DC then the action is immediate and the HIZ l e d is turned off If the meter is set to any other function then the next time Volts DC is selected it will be low impedance on all ranges HIZ Sequential command Function Change command see note above Operation complete message generated immediately after execution Set the Volts DC function to high input impedance gt 1GQ on the 210mV and 2 1V ranges If the meter is presently set to Volts DC then the action is immediate and the HIZ l e d is lit if the meter is set to either the 210mV or 2 1V range If the meter is set to any other function then the next time Volts DC is selected it will be high impedance on the bottom two ranges FAST Sequential command Operation complete message generated immediately after execution Sets 4 digit mode If already in this mode no action is taken SLOW Sequential command Operation complete message generated immediately after execution Sets 5 digit mode If already in this mode no action is taken TREAD Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns one reading immediately after a
46. here are no control handshake lines This makes XON XOFF protocol essential and allows the inter connection between instruments to contain just 3 wires The wiring of the adaptor cable is shown below TO NEXT INSTRUMENT 9 WAY D 9 WAY D FEMALE MALE DCD 1 O1 RX 20 O2 TX TX m 30 O3 aAm RX DTR 4 O4 GND sO s GND DSR 6 Os RTS A e 7 O7 CTS ERN O8 RI 90 X O9 LINKS TO CONTROLLER A CHAIN S lt O OOOO OO sSwYD 12345 6789 MAE AN INSTRUMENT l ON THE CHAIN TX RX TXIN RXOUT All instruments on the interface must be set to the same baud rate and all must be powered on otherwise instruments further down the daisy chain will not receive any data or commands The ARC standard for the other interface parameters is as follows Start bits 1 Data bits 8 Parity None Stop bits 1 In this multimeter as with most other ARC instruments these parameters are fixed ARC Character Set Because of the need for XON XOFF handshake it is possible to send ASCII coded data only binary blocks are not allowed Bit 7 of ASCII codes is ignored i e assumed to be low No distinction is made between upper and lower case characters in command mnemonics and they may be freely mixed The ASCII codes below 20H space are reserved for interface control ARC Interface Control Codes 22 All instruments intended for use on the ARC bus use the fo
47. ings up to the maximum number required There are ten possible digital filter selections available each gives various combinations of n and j they are numbered 0 9 Filter O is the default value whereby each meter function and range has its own optimised values of n and j The values for the other selections is shown in Table 1 To change the filter value press PROG followed by FILTER The display shows FLtr and the current selection number 0 9 The selection number may be changed either directly by pressing the appropriate numerical key or by pressing the RANGE A and RANGE V down keys to scroll through 0 9 When the required filter selection number is shown press ENTER to store the new filter value Filter j Defaults Defaults 1 0 w NIN C2 0 Defaults por 8 EE E E ee 6 32 pom 32 ee eee ee o9 32 Table 1 Filter Values dB deciBel Calculations Setting Up and Running dB 14 Decibel calculations are initiated by pressing PROG followed by dB Note that meter function changes are inhibited whilst in the dB readout mode so it is necessary to select the required function before entering the dB program The dB program may not be run whilst A is also running inPro is displayed Using A When the GB program is selected it first displays the existing reference value The value s units are fixed at V kQ or mA depending upon whether the meter is currently measuring voltage resistance
48. ings will be recorded regularly at the sample period set as one of the logger parameters If the logger trigger is external then a reading will be recorded after every subsequent TRG is received If the logger is set to a linear store and 100 samples have already been stored then TRG will cause no action to be taken If the logger is recording automatically at timed intervals then no action will result from TRG commands after the first one If the data logger is not running and the instrument has already received a triggered reading request TREAD then this command will trigger the response Note that when the instrument is operating on the GPIB the GET message performs the same functions as TRG TST Sequential command Operation complete message generated immediately after rmt is sent The multimeter has no self test capability and the response is always O rmt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode WAI Sequential command Operation complete message generated immediately after execution Wait for operation complete true As all commands are completely executed before the next is started this command takes no additional action Instrument Specific Commands 32 The commands in this section are additional to those specified by IEEE Std 488 2 as Common Commands Note If the meter is currently reading out in AX B A or dBs or
49. l Enable Register is ANDed with the Status Byte Register if the result is zero then the value of ist is O otherwise the value of ist is 1 The instrument must also be configured so that the value of ist can be returned to the controller during a parallel poll operation The instrument is configured by the controller sending a Parallel Poll Configure command PPC followed by a Parallel Poll Enable command PPE The bits in the PPE command are shown below a 0 sense of the response bit 0 low 1 high Example To return the RQS bit bit 6 of the Status Byte Register as a 1 when true and a 0 when false in bit position 1 in response to a parallel poll operation send the following commands PRE 64 lt pmt gt then PPC followed by 69h PPE The parallel poll response from the power supply will then be 00h if RQS is 0 and Oth if RQS is 1 During parallel poll response the DIO interface lines are resistively terminated passive termination This allows multiple devices to share the same response bit position in either wired AND or wired OR configuration see IEEE 488 1 for more information POWER ON SETTINGS Most instrument settings are stored in non volatile ram and will remain unchanged while power is off The following instrument status values are set at power on Status Byte Register 0 x Service Request Enable Register 0 Standard Event Status Register 128 pon bit set x Standard Event Status Enable Register 0 Execution
50. lar Category Il does not include distribution level supplies e g three phase installations which are classified as Installation Category Ill Use of this instrument in a manner not specified by these instructions may impair the safety protection provided Do not operate the instrument outside its rated supply voltages or environmental range In particular excessive moisture may impair safety WARNING THIS METER MUST BE EARTHED Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited The protective action must not be negated by the use of an extension cord without a protective conductor The mains plug must be inserted before connections are made to circuits being measured When the instrument is connected to its supply or its inputs are connected to live voltages terminals may be live and opening the covers or removal of parts except those to which access can be gained by hand is likely to expose live parts The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment replacement maintenance or repair Any adjustment maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and if inevitable shall be carried out only by a skilled person who is aware of the hazard involved If the instrument is clearly defective has been subject to mechanical damage excessive mois
51. le mode or when addressed to talk if in addressable mode Example MIN MAX VOLTS DC 2 10000E 1 OVERLOAD HOLDON Sequential command Operation complete message generated immediately after execution Turn on the T HOLD display mode If the mode is already active then this command will cause the display to unfreeze and follow the measurements until the next stable non zero reading is obtained If the display is not being held when the command is received then no action will result HOLDOFF Sequential command Operation complete message generated immediately after execution Cancel T HOLD display mode If T HOLD mode not active no action will be taken LOGON lt nrf gt lt nrf gt lt nrf gt Sequential command Operation complete message generated immediately after execution Turn on the data logger sending optional logger parameters With or without parameters this command causes the logger to enter the ready condition in which the logger is completely set up and is waiting for the first TRG or GET if GPIB to start storing data The LOG l e d is lit and the display flashes ready intermittently The three parameters are in the required order Parameter 1 Time interval between automatically triggered samples with permitted values between 0 and 9999 seconds Parameter 2 Automatic External trigger encoded as 1 0 respectively Parameter 3 Linear Circular store encoded as 1 0 respectively Example LOGON 1234
52. lies with EN61010 1 Complies with EN61326 Safety This instrument is a Safety Class 1 according IEC classification and has been designed to meet the requirements of EN61010 1 Safety Requirements for Electronic Equipment for Measurement Control and Laboratory Use It is an Installation Category II instrument intended for operation from a normal single phase supply This instrument has been tested in accordance with EN61010 1 and has been supplied in a safe condition This instruction manual contains some information and warnings which have to be followed by the user to ensure safe operation and to retain the instrument in a safe condition This instrument has been designed for indoor use in a Pollution Degree 1 environment no pollution or only dry non conductive pollution in the temperature range 5 C to 40 C 20 80 RH non condensing It may occasionally be subjected to temperatures between 5 C and 10 C without degradation of its safety It has been designed for Installation Category measurement use to 1000 V and Installation Category Il measurement use to 600V The full definitions of Categories and II can be found in IEC664 but the following can be taken as a guide Installation Category is signal level e g telecommunication electronic equipment with smaller transient overvoltages than Installation Category II Installation Category II is local domestic supply level e g portable equipment and appliances In particu
53. ll in this case be automatically cancelled if the dB program is cancelled One set of Ax B parameters are reserved for scaling dB readouts These are preserved when the Ax B is cancelled dB readouts can be compared with dB limits by running the LIMITS program while the dB program is running A set of high and low limit values is reserved for dB comparison As with normal limits testing a P H or L is displayed on the right most digit to indicate the result of the comparison If the dB readouts are also scaled by Ax B then the comparison performed using the Ax B scaled readout Maximum and minimum dB measurements can be recorded by starting the recording while the dB program is running dB readouts can be logged by invoking the logger in the usual way see Data Logger section while the dB program is running Note however that the stored results will be lost when dB is cancelled T HOLD display is possible while running dB Deviation Calculations Setting Up and Running A Deviation calculations are initiated by pressing PROG followed by A Note that meter function changes are inhibited whilst in the A readout mode so it is necessary to select the required function before entering the A program The A program may not be run whilst dB is also running in Pro is displayed When the program is selected it first displays the existing floating point reference value which may be re entered by pressing ENTER Alternatively it may first be edited
54. llowing set of interface control codes Codes between 00H and 1FH which are not listed here as having a particular meaning are reserved for future use and will be ignored Mixing interface control codes inside instrument commands is not allowed except as stated below for CR and LF codes and XON and XOFF codes When an instrument is first powered on it will automatically enter the Non Addressable mode In this mode the instrument is not addressable and will not respond to any address commands This allows the instrument to function as a normal RS232 controllable device This mode may be locked by sending the Lock Non Addressable mode control code 04H LNA The controller and instrument can now freely use all 8 bit codes and binary blocks but all interface control codes are ignored To return to addressable mode the instrument must be powered off To enable addressable mode after a instrument has been powered on the Set Addressable Mode control code 02h SAM must be sent This will then enable all instruments connected to the ARC bus to respond to all interface control codes To return to Non Addressable mode the Lock Non Addressable mode control code must be sent which will disable addressable mode until the instruments are powered off Before an instrument is sent a command it must be addressed to listen by sending the Listen Address control code 12H LAD followed by a single character which has the lower 5 bits corresponding to the unique addres
55. mand Operation complete message generated immediately after execution Set the digital filter parameters to selection lt nrf gt There are ten possibilities 0 9 detailed in Table 1 Example FILTER 0 sets the digital filter to the default values optimised for each range and function If the value of lt nrf gt after rounding is outside the range 0 9 then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register TRGSET lt nrf gt Sequential command Operation complete message generated immediately after execution Set the type of triggered reading that will result from a TREAD query If lt nrf gt 0 then the next reading after receipt of a TRG or GET if GPIB will be returned If lt nrf gt 1 then the instrument will return the next stable reading following receipt of a TRG or GET if GPIB The reading is judged to be stable when the digital filter has seen n readings all within j of each other This will therefore change with filter setting see Table 1 If the lt nrf gt values sent with this command are not permissible values after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register BUZZ lt nrf gt lt nrf gt lt nrf gt Sequential command Operation complete message generated immediately after execution Set up the buzzer parameters in the required order Parameter 1 continuity
56. n the Execution Error Register LIMITS lt nrf gt lt nrf gt Sequential command Operation complete message generated immediately after execution Start the LIMITS comparison program using the optionally sent lt nrf gt parameters The parameters are sent low limit followed by high limit and are required in Volts mAmps or kQ If no parameters are sent then existing limits are used Note that different limits can be set for each basic meter function in addition to limits for dB and A readouts see Advanced Features section The limits sent with this command will be stored for the meter function currently operating when the command is received If the lt nrf gt values sent with this command are not permissible values after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register The permissible values for the basic meter function limits are the same as listed in Table 2 for the B values of Ax B The permissible values for dB and A limits are as follows dB 999 99 to 999 99 A 999 999 to 999 999 If only one parameter is sent then a Command Error will be reported in the Standard Event Status register LIMOFF Sequential command Operation complete message generated immediately after execution Stop the LIMITS program from operating If The LIMITS program is not operating then no action is taken COMP Sequential command Operation complete message
57. ncelled refer to the appropriate section in ADVANCED FEATURES When V DC is selected a high input impedance of gt 1GQ HI Z is available on the 200mV and 2V ranges Successive presses of the V key toggle HI Z on and off when the meter switched to either the 200mV or 2V DC ranges The HI Z l e d indicates when the input is actually high impedance If HI Z has been selected the l e d will turn off automatically when the meter is switched to 20V and above and on again when the meter is in the 200mV or 2V ranges Range Selection If the signal input to the meter is too big for the range then OL is displayed and a higher range must be selected if there is one This may be done automatically or manually Autoranging mode is selected by pressing the AUTO key When in autorange mode the l e d above the AUTO key is lit and the meter will automatically select a range where the reading is between full scale and 5 of full scale Successive presses of the AUTO key toggle autoranging on and off Meter ranges are selected manually by pressing either the RANGE A key or the RANGE V key If the meter is in autorange then pressing either of these keys selects manual ranging deselects autoranging and the AUTO l e d is extinguished If the meter function is changed the range just prior to the change is stored This allows the meter to switch automatically to the same range if the first function is again selected This can save time when switching between
58. ommand Operation complete message generated immediately after execution Set the Standard Event Status Enable Register to the value of lt nrf gt If the value of lt nrf gt after rounding is less than O or greater than 255 an execution error is generated and error number 119 out of range is placed in the Execution Error Register ESE Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value in the Standard Event Status Enable Register in lt nr1 gt numeric format The syntax of the response is lt nr1 gt lt rmt gt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode Example If the Standard Event Status Enable Register contains 01000001b the response to ESE will be 65 lt rmt gt ESR Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value in the Standard Event Status Register in lt nr1 gt numeric format The register is then cleared The syntax of the response is lt nr1 gt lt rmt gt 29 30 On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode Example If the Standard Event Status Register contains 01000001b the response to ESR will be 65 lt rmt gt IDN Sequential command Operation complete message generated immediately after rmt
59. ommands and queries implemented in this multimeter Note that there are no dependent parameters coupled parameters overlapping commands expression program data elements or compound command program headers and that each command is completely executed before the next command is started The following command sections use the following nomenclature lt pmt gt lt PROGRAM MESSAGE TERMINATOR gt lt rmt gt lt RESPONSE MESSAGE TERMINATOR gt lt nrf gt A number in any format e g 12 12 00 1 2 e1 and 120 e 1 are all accepted as the number 12 Any number when received is converted to the required precision consistent with the use then rounded up to obtain the value of the command lt nr1 gt A number with no fractional part i e an integer nr2 A number in fixed point format e g 11 52 0 78 etc Any item s enclosed in these brackets are optional parameters If more than one item is enclosed then all or none of the items are required Common Commands The commands in this section are those specified by IEEE Std 488 2 as Common commands All will function when used on the ARC interface but some are of little use CLS Sequential command Operation complete message generated immediately after execution Clear status Clears the Standard Event Status Register Limit Event Status Register Query Error Register and Execution Error Register This indirectly clears the Status Byte Register ESE lt nrf gt Sequential c
60. ons are possible When the instrument is addressed to listen and a command is received the remote state will be entered and the REMOTE led will be turned on In this state the keyboard is locked out and remote commands only will be processed The instrument may be returned to the local state by pressing the LOCAL key however the effect of this action will remain only until the instrument is addressed again or receives another character from the ARC interface when the remote state will once again be entered ARC INTERFACE ARC Interface Connections The 9 way D type serial interface connector is located on the instrument rear panel The pin connections are as shown below Pin Name Description 1 No internal Connection 2 TXD Transmitted data from instrument 3 RXD Received data to instrument 4 No internal connection 5 GND Signal ground 6 No internal connection 7 RXD2 Secondary received data see diagram 8 TXD2 Secondary transmitted data see diagram 9 GND Signal ground 21 Pins 2 3 and 5 may be used as a conventional RS232 interface with XON XOFF handshaking Pins 7 8 and 9 are additionally used when the instrument is connected to the ARC interface Using a simple cable assembly a daisy chain connection system between any number of instruments up to the maximum of 32 can be made as shown below CONTROLLER ade i dod scd The daisy chain consists of the transmit data TXD receive date RXD and signal ground lines only T
61. or current The value may be re entered by pressing ENTER or it may be edited first as described above for fixed decimal point numbers or if CANCEL is pressed the dB program will be individually cancelled and the display will return to the previous mode The program starts when ENTER is pressed Once the dB program is running the display shows the calculated result followed by the letters dB no units l e d s are lit The dB program performs a generalised calculation READING v REF Where REF is the user entered reference value If REF is entered as 1 000 then the above calculation provides dBV dBkO or dBmA depending on whether the meter is set up to measure voltage resistance or current dBm dB relative to 1mW readouts are obtained by setting REF to the required reference impedance in kO whilst measuring voltage By NULLing the reading before initiating the dB program all calculations are made on measurements offset by the null value If NULL is pressed while the dB program is running then the display will show dB values relative to the measured value when the NULL key was pressed 20log dB with other programs The dB calculations can be performed on Ax B scaled readings In this case the parameters must be set up before running the dB program In addition Ax B scaling can be performed upon the results of dB calculations In this case the Ax B scaling should be invoked while the dB program is running Note that the Ax B program wi
62. ore the parser is allowed to start the next command in the input queue Commands are sent as PROGRAM MESSAGES by the controller each message consists of zero or more PROGRAM MESSAGE UNIT elements separated by PROGRAM MESSAGE UNIT SEPARATOR elements PROGRAM MESSAGES are separated by PROGRAM MESSAGE TERMINATOR elements which may be any of the following NL The new line character OAH NL END The new line character with the END message END The END message with the last character of the message A PROGRAM MESSAGE UNIT SEPARATOR is the semi colon character 3BH A PROGRAM MESSAGE UNIT is any of the commands in the REMOTE COMMANDS section Responses from the instrument to the controller are sent as RESPONSE MESSAGES A RESPONSE MESSAGE consists of one RESPONSE MESSAGE UNIT followed by a RESPONSE MESSAGE TERMINATOR A RESPONSE MESSAGE TERMINATOR is the new line character with the END message NL END Each query produces a specific RESPONSE MESSAGE which is listed along with the command in the REMOTE COMMANDS section WHITE SPACE is ignored except in command identifiers e g C LS is not equivalent to CLS WHITE SPACE is defined as character codes 00H to 20H inclusive with the exception of the NL character OAH The high bit of all characters is ignored except in binary blocks The commands are case insensitive Remote Commands The following sections list all c
63. pt d EN61000 4 4 2004 Fast Transient e EN61000 4 5 2006 Surge f EN61000 4 6 2007 Conducted RF Performance levels achieved are detailed in the user manual Safety Multimeter EN61010 1 Installation Category measurements to 1000V Installation Category Il measurements to 600V Pollution Degree 1 Probes IEC1010 2 031 Rated to 1000V Installation Category III CHRIS WILDING TECHNICAL DIRECTOR 1 May 2009 EMC This instrument has been designed to meet the requirements of the EMC Directive 2004 108 EC Compliance was demonstrated by meeting the test limits of the following standards Emissions EN61326 1 2006 EMC product standard for Electrical Equipment for Measurement Control and Laboratory Use Test limits used were a Radiated Class B b Conducted Class B c Harmonics EN61000 3 2 2006 Class A the instrument is Class A by product category Immunity EN61326 1 2006 EMC product standard for Electrical Equipment for Measurement Control and Laboratory Use Test methods limits and performance achieved are shown below requirement shown in brackets a EN61000 4 2 1995 Electrostatic Discharge 4kV air 4kV contact Performance B B b EN61000 4 3 2006 Electromagnetic Field 3V m 80 AM at 1kHz 80MHz 1GHz Performance B A and 1 4GHz to 2GHz Performance A A 1V m 2 0GHz to 2 7GHz Performance A A c EN61000 4 11 2004 Voltage Interrupt 72 cycle and 1 cycle 0 Performance A B
64. red to be in Volts mAmps or KQ for basic meter functions The range of permissible B values is listed in Table 2 For dB calculations the B value is required to be in dBs with the same range as A If no parameters are sent then existing values are used If the Ax B program is already operating then this command will cause it to continue with the new values if sent Note that different parameter values can be stored for each basic meter function in addition to values for dB readouts see Advanced Features section The values sent with this command will be stored for the meter function currently operating when the command is received If the lt nrf gt values sent with this command are not permissible values after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register AXBOFF Sequential command Operation complete message generated immediately after execution Stop the Ax B program from operating If the Ax 8 program is not operating then no action is taken 37 38 MMON Sequential command Operation complete message generated immediately after execution Start the MIN MAX recording mode initially setting both MIN and MAX values to the same reading value If MIN MAX is already operating then reset the MIN and MAX values to the same reading and restart recording Note that a delay of five readings is imposed between receiving this command and starting the recor
65. rfaces and other equipment b After opening the case for any reason ensure that all signal and ground connections are remade correctly and that case screws are correctly refitted and tightened c In the event of part replacement becoming necessary only use components of an identical type see the Service Manual Installation Mains Operating Voltage Check that the instrument is set up for the required operating voltage The operating voltage is set by the orientation of the fuse drawer located immediately under the mains socket The selected operating voltage is shown by the printing which is at the top of the fuse drawer when the instrument is the right way up The fuse drawer can be rotated by first withdrawing it from the mains socket housing with the power plug removed and then reinserting it Ensure that the correct mains fuse is fitted for the operating voltage selected The correct mains fuse types are for 230V operation 125mA T 250V for 115V operation 250mA T 250V Mains Lead When a three core mains lead with bare ends is provided it should be connected as follows BROWN MAINS LIVE BLUE MAINS NEUTRAL GREEN YELLOW MAINS EARTH WARNING THIS METER MUST BE EARTHED Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited The protective action must not be negated by the use of an extension cord without a protectiv
66. ror 2 failure may be due to a faulty or exhausted battery in which case the meter can be operated normally except that nothing will be retained at switch off However care should taken to ensure that the meter is operating properly as the fault may also be due to a faulty RAM chip Default Instrument Settings The multimeter is put into the following default condition as a result of a recall of store 9 remote or local a remote RST command or a RAM error at power up e 5 Digit mode set e Meter function set to Volts DC e Meter range set to 1KV e Autoranging mode set e All computational programs cancelled e T HOLD cancelled e Continuity buzzer turned off e Digital Filter set to range dependant defaults e Data Logger cancelled stored data lost logger parameters set to circular store automatic trigger with sample period set to 0000 seconds e Remote reading trigger set to immediate e All Ax B scaling factors set to A 1 00000 and B 0 00000 e All LIMITS set to 0 00000 e A reference value set to 0 00000 e dB reference value set to 1 000 e MIN MAX data invalid e Bus address set to 1 not set if in remote state e Baud rate set to 9600 not set if in remote state Remote Operation The following sections detail the operation of the instrument via both GPIB and ARC Where operation is identical no distinction is made between the two Where differences occur these are detailed in the appropriate sections or in some cases separat
67. s for post processing readings to produce scaled logged or compared results all of which require numerical parameters to be entered Floating point numbers are entered directly as individual digits at the flashing edit point using the red numeric keys The position of the flashing edit point may be moved through the number by presses of the STEP EDIT key The edit cursor wraps round from the least significant digit to the most significant digit The position of the decimal point may be changed using the SCROLL key Where the numerical value has units e g mV the appropriate displayed units l e d is lit and the SCROLL key moves the decimal point in conjunction with the units l e d s through the permitted possibilities For numbers with no units the decimal point is simply stepped right wrapping round to the left when it reaches the right hand end The sign can be toggled using the key Once the complete value has been set up on the display pressing ENTER stores the value and either the program commences operation or the next parameter is displayed for editing if more than one parameter is required If CANCEL is pressed before the last parameter of a particular program is ENTERed then operation of that program is cancelled Fixed decimal point numbers are entered directly at a flashing edit digit as for floating point numbers except that the SCROLL key has no effect on the decimal point position Where the choice is limited to only a few entries the
68. s of the required instrument e g the codes A Z or a z give the addresses 1 26 inclusive while is address 0 and so on Once addressed to listen the instrument will read and act upon any commands sent until the listen mode is cancelled Because of the asynchronous nature of the interface it is necessary for the controller to be informed that an instrument has accepted the listen address sequence and is ready to receive commands The controller will therefore wait for code 06H ACK before sending any commands The addressed instrument will provide this ACK The controller should time out and try again if no ACK is received within 5 seconds Listen mode will be cancelled by any of the following interface control codes being received 12H LAD Listen Address followed by an address not belonging to this instrument 14H TAD Talk Address for any instrument 03H UNA Universal Unaddress control code 04H LNA Lock Non Addressable mode control code 18H UDC Universal Device Clear Before a response can be read from an instrument it must be addressed to talk by sending the Talk Address control code 14H TAD followed by a single character which has the lower 5 bits corresponding to the unique address of the required instrument as for the listen address control code above Once addressed to talk the instrument will send the response message it has available if any and then exit the talk addressed state Only one response message will be sent each time the in
69. sic meter function DBOFF Sequential command Operation complete message generated immediately after execution Cancel dB post proccessing of measurements If dB computations not currently active then no action will be taken DEV lt nrf gt Sequential command Operation complete message generated immediately after execution Start the A readout mode about the optionally sent lt nrf gt reference value If no reference value is sent then the existing value is used If the lt nrf gt value sent with this command is not a permissible value after rounding then an execution error is generated and error number 119 Out of Range is placed in the Execution Error Register The permissible values for the A reference depend on the selected basic meter function and are the same as listed in Table 2 for the B values of Ax B The units of the reference will depend on the selected basic meter function DEVOFF Sequential command Operation complete message generated immediately after execution Cancel A post proccessing of measurements If A computations not currently active then no action will be taken AXB lt nrf gt lt nrf gt Sequential command Operation complete message generated immediately after execution Start the Ax B scaling program using the optionally sent lt nrf gt parameters The parameters are sent A value followed by B value The A value can be any numerical value between and 999999 The B value is requi
70. strument is addressed to talk Talk mode will be cancelled by any of the following interface control codes being received 12H LAD Listen Address for any instrument 14H TAD Talk Address followed by an address not belonging to this instrument 03H UNA Universal Unaddress control code 04H LNA Lock Non Addressable mode control code 18H UDC Universal Device Clear Talk mode will also be cancelled when the instrument has completed sending a response message or has nothing to say The interface code OAH LF is the Universal Command and response Terminator UCT it must be the last code sent in all commands and will be the last code sent in all responses The interface code ODH CR may be used as required to aid the formatting of commands it will be ignored by all instruments Most instruments will terminate responses with CR followed by LF The interface code 13H XOFF may be sent at any time by a listener instrument or controller to suspend the output of a talker The listener must send 11H XON before the talker will resume sending This is the only form of handshake control supported by ARC 23 ARC Interface Control Code List 02H SAM _ Set Addressable mode 03H UNA Universal Unaddress control code 04H LNA Lock Non Addressable mode control code 06H ACK Acknowledge that listen address received OAH UCT Universal Command and response Terminator ODH CR Formatting code otherwise ignored 11H XON Restart transmission 12H
71. t up press STORE followed by the number of the store 0 5 The operation may be cancelled without storing anything by pressing CANCEL instead of a number If key is pressed other than CANCEL that does not represent a valid store number then no StorE is displayed To recall an instrument set up press PROG followed by RECALL followed by the number of the store 0 5 The operation may be cancelled without recalling a set up by pressing CANCEL instead of a number If a key is pressed that does not represent a valid store number except for CANCEL then no StorE is displayed If a valid store number is pressed but no set up has ever been stored in that store then no dAtA is displayed A default setup can be recalled using PROG RECALL 9 This briefly displays dEFAULt whilst setting default values as listed in the DEFAULT INSTRUMENT SETTINGS section All previously running programs are cancelled Data Logger Introduction To The Data Logger The data logger can store up to 100 measurements or post processed results and is configurable to be linear or circular The linear logger stops storing after 100 measurements The circular logger does not stop at 100 measurements but continues storing overwriting the oldest data with the newest until it is stopped When 100 locations have been filled an F is shown at the right most character of the display The measurement samples may be triggered automatically on a timed basis or by an external trigger which may
72. ta contains three fields separated by dashes nnn SAMPLES units data where nnn is the number of samples stored in the data logger units are the units of the basic meter function and data is the formated data field The basic meter function units are VOLTS DC VOLTS AC MILLIAMPS DC MILLIAMPS AC KOHMS This field is fourteen characters wide between dashes The data field contains up to 100 elements separated by commas Each element contains fourteen characters giving the store location followed by the data stored at that location in the same format as described for the TREAD query NN n nnnnnEzn NN nnn nnDB NN nnn nnn96 NN OVERLOAD NN OVERFLOW where NN is the store location and n is a decimal number Examples 00 0 12345E 1 99 120 00DB If the store contains no data then the response syntax is DATA LOGGER NO DATA On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode Example DATA LOGGER 3 SAMPLES VOLTS DC 00 2 10000E 1 01 OVERLOAD 02 0 00001E 1 PAUSE Sequential command Operation complete message generated immediately after execution Stop the data logger storing readings and enter the ready condition Data storage may be restarted by issuing a TRG or GET if GPIB command without overwriting existing data If the data logger is not active then no action will be taken FILTER lt nrf gt Sequential com
73. ture or chemical corrosion the safety protection may be impaired and the apparatus should be withdrawn from use and returned for checking and repair Make sure that only fuses with the required rated current and of the specified type are used for replacement The use of makeshift fuses and the short circuiting of fuse holders is prohibited Do not wet the instrument when cleaning it The following symbols are used on the multimeter and in this manual h WARNING risk of electric shock m direct current CAUTION refer to accompanying documentation u alternating current incorrect operation may damage the meter mains earth ground EC Declaration of Conformity We Thurlby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England declare that the Model 1906 Computing Multimeter and Model 1906GP Computing Multimeter with GPIB meets the intent of the EMC Directive 2004 108 EC and the Low Voltage Directive 2006 95 EC Compliance was demonstrated by conformance to the following specifications which have been listed in the Official Journal of the European Communities EMC Emissions a EN61326 1 2006 Radiated Class B b EN61326 1 2006 Conducted Class B c EN61326 1 2006 Harmonics referring to EN61000 3 2 2006 Immunity EN61326 1 2006 Immunity Table 1 referring to a EN61000 4 2 1995 Electrostatic Discharge b EN61000 4 3 2006 Electromagnetic Field c EN61000 4 11 2004 Voltage Interru
74. ual Performs range up operation if not in calibrate mode 41 SETCAL lt nrf gt Sequential command Operation complete message generated immediately after execution Used for meter calibration only refer to service manual If not in calibrate mode then no action is taken EER Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value in the Execution Error Register in lt nr1 gt numeric format The register is then cleared The syntax of the response is lt nr1 gt lt rmt gt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode QER Sequential command Operation complete message generated immediately after lt rmt gt is sent Returns the value in the Query Error Register in lt nr1 gt numeric format The register is then cleared The syntax of the response is lt nr1 gt lt rmt gt On the serial interface the response is sent immediately if in non addressable mode or when addressed to talk if in addressable mode Remote Command Summary Common Commands 42 CLS Clear Status ESE lt nrf gt Set the Standard Event Status Enable Register to the value of lt nrf gt ESE Returns the value in the Standard Event Status Enable Register ESR Returns the value in the Standard Event Status Register IDN Returns the instrument identification IST Returns ist local message
75. user entered references and scaling factors retention of logged data Software calibration with constants stored in EEPROM Specification Accuracy Accuracies apply for 1 year 18 C to 26 C Temperature coefficient outside these limits is lt 0 1 x quoted range accuracy per C Warm up time to rated accuracy is 1 hour DC Volts Range Accuracy Input Impedance Max Input 200mV 0 017 3d 10MQ or gt 1GQ 2V 0 012 3d 1kV DC or AC 20V 0 019 3d Peak any range 200V 0 019 3d 10MQ 1000V 0 019 3d Resistance Ohms Range Accuracy Max Measuring Current Max Input 200 0 025 4d 1 5mA 2k 0 019 3d 1 5mA 300V DC or RMS 20k 0 019 3d 0 4mA continuous any 200k 0 019 3d 40pA Ohms input any 2M 0 022 3d 4UuA range 20M 0 07 3d 400nA Max open circuit voltage 3 5V Audible continuity check available on all ranges AC Volts True RMS Accuracy Range 45Hz 5kHz 5kHz 10kHz 10KHz 20kHz 20kHz 50kHz 200mV 0 296 150d 0 2 250d 3 500d 2V 0 296 150d 0 2 250d 0 5 300d 3 1500D 20V 0 296 150d 0 2 250d 0 5 300d 2 1000D 200V 0 2 150d 0 2 250d 0 5 500d 750V 0 2 150d Accuracy specifications apply for readings between 10 and 100 of full scale Additional error at crest factor 3 typically 0 796 Input impedance 1MQ 100 pF any range Max input 750V rms 1kV
76. value from all subsequent readings made in that meter function until NULL is cancelled Because the null value is stored as a real value the same amount is subtracted from all reading regardless of range i e if 100mV is stored as the null value then 100mV will be subtracted from all measurements even if they are made in the 1kV range A separate null value can be stored for all basic meter functions plus one for nulling after dB calculations The NULL l e d indicates that a null value has been stored for a particular function and will switch on or off if the function is changed depending on whether a null value has been previously stored for the new function The null operation is performed on all measurements before any further post processing with one exception If the NULL value is stored while the dB program is in progress then the null value is in dBs and is subtracted from the result of the dB calculations If the null value is stored before invoking dB then the nulling is performed before the dB calculations are made 13 Buzzer Filter The buzzer can be programmed to indicate up to three conditions continuity the limits comparison showing the measurement to be within or outside of set limits and the occurrence of a data logger trigger To program the buzzer press PROG followed by BUZZER The three buzzer selections are then displayed sequentially by repeated presses of the SCROLL key The first selection shown when entering the buzzer e
77. ws common levels of key function Primary level functions are indicated above the keys in black and are accessed by a single key stroke Secondary level functions are shown below the keys in blue and are accessed by first pressing the PROG key Tertiary level functions are shown in red these are mostly for entering numerical data and for examining logged data Above most of the keys are l e d s which indicate that the primary key function has been selected Manual range selection and auto manual ranging are primary functions of the three keys grouped on the right hand side of the keyboard All basic meter functions are selected as primary functions of the six keys to left of the range keys Remote control functions are grouped bottom left of the keyboard The six input sockets are colour coded black sockets being considered less positive compared to red and white The black socket marked V Q A serves as the common terminal for all measurements and is connected to analogue common CAL SWITCH WITH INDICATOR ACTIVE COMPUTATION DISPLAYED UNTS LEDS CONTINUITY LED INPUT MAIN DISPLAY SOCKETS Ji THUR LY VTHANDAR 1906 donut MULTIMETER Seater eer ie gt HI ica O O mn A SENSE vin wa TO O Iman Ae LO o j m MinMexi O GENF Mes O SENSE O O V Q A REMOTE O O O OO O O STORE PROG NULL V HZ mA 0A RANGE A LO LL ib JieL_J sL

User Manual - Test It Now

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