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Model 4300C - Valhalla Scientific, Inc

1. Current Range The two keys labeled F S Voltage are used to change the voltage setting The key is used to increase the voltage setting and the key is used to decrease the setting Within a voltage setting there are six possible Ohm Ranges The two keys labeled Q Range are used switch between the ranges The key is used to increase the range and the Y key is used to decrease the range As the Ohms range increases the current range decreases and vice versa Test Current ON em Test CURRENT Figure 23 Test Current To engage or disengage the Test Current press the Test Current key located on the front panel A red LED within the Test Current key indicates the status of the current source The current source may also be turned on and off via a command from one of the interfaces or by a remote footswitch using Option RS Chapter 3 Getting Started Charging Inductor Mode The Charging Inductor mode LED indicates when the standard current source compliance voltage of 7V is exceeded In this situation the 4300C provides a booster shot in excess of 20V to reduce the settling time when a large inductive load is being measured The display readings should be ignored when this LED is illuminated Cable Disconnect Status Indicators The SAFE and UNSAFE LED s indicate whether or not it is safe to disconnect the test leads from the load When a highly inductive load is being measured a potentially lethal back EMF is i
2. Figure 41 Controller 2 5V Ref 32 768kHz U2 Oscillator X1 Keypad J7 Latches to Kad U6 U9 yP u Controller BCD IEEE Latches zeen J8 U10 U12 ech SG 3 Sensor U1 Indicator 311 Latches to 4300B 701 EN Over Voltage U13 U15 lat Protection DA HLC Relays D6 D8 Q2 Q4 Current cde Selector RS 232 Display Latches Buzzer Switch U5 310 U17 L to Display to 4300C 700 RS 232 Driver Receiver Download Operate U16 J3 J17 Micro Controller The micro controller executes the analog to digital conversion on the voltage across the load Also all other processes such as range selection HLC relay switching LEDs activation and so on Refer to schematic 834u 070 sheet 1 Over Voltage Protection The resistor R9 and diode D1 thru D4 form the Over Voltage protection circuitry This block limits the input voltage to only 7V if an extreme overload occurs Refer to schematic 834u 070 sheet 1 TCM The zener diode D5 and its associated components create a 1 2V reference This voltage level plus AVDD are used to power the temperature compensator if attached Refer to schematic 834u 070 sheet 1 7 7 4300C User Manual 2 5V Reference U2 is a precision 2 5V reference used by the micro controller during the analog to digital conversion Refer to schematic 834u 070 sheet 1 RS 232 Display Switch and RS 232 Driver Receiver
3. Pin Function No connection Receive Data RxD input Transmit Data TxD output No connection Signal Ground GND No connection No connection No connection No connection Figure 16 9 Pin Table 5 RS 232 Pin out RS 232 Connector LD ON On Un PS 0 NN ta APPLYING POWER Chapter 3 Getting Started Before applying power please refer to Chapter 1 for safety precisions Turn on the ohmmeter by placing the front panel power switch in the ON position If the ohmmeter does not turn on verify that the instrument is connected to the power line If line power is not the problem remove the power cord and check the line power fuse and the line voltage selection switch settings POWER ON DEFAULT SETTINGS Figure 17 Display Power Up Messages UST 44880 GOhrmmeter Fel Version Pour loadin as EST Mex pr oc LISPI SJ Menor Functions Standard Measurement Mode Voltage Setting Range TCM Temperature Compensation Mode HLC Hi Lo Comparator Mode BCD binary Coded Decimal Output PIM Printer Log Mode Table 6 Power Up Defaults Once on the ohmmeter performs its power on routine On the display you should see the messages in Figure 17 When the power on routine is finished the ohmmeter will beep twice The power on routine will default the ohmmeter s functions as described in the following table Setting ON 2V 20kQ OFF OFF OFF OFF 4300C User Manual CONNEC
4. CALDATE QUERY Request the last calibration date and technician initials Syntax CALDATE Response 00 00 04 VSI Power on default 00 00 00 VSHHHH CLS COMMAND Sets buffers to power on default Syntax CLS lt crlf gt CNFG COMMAND Turns on and off system configuration items Alarms key beeps other features Syntax CNFG lt item number gt lt ON or OFF gt Example CNFG 1 ON lt crlf gt CNFG 1 lt crlf gt ON lt crlf gt 1 Suppress Alarms 2 Suppress Key Beeps Power on defaults OFF CNFG QUERY Responds with CNFG mode on or off Syntax CNFG Example CNFG 2 lt crlf gt ON lt crlf gt Response lt ON or OFF gt 1 Suppress Alarms 2 Suppress Key Beeps Power on defaults OFF pleasantly noisy FAULT COMMAND Chapter 6 Remote Operations RS 232 Interface Sets an alarm fault to watch the system react Syntax FAULT lt Hexadecimal number gt FAULT_ALARM_NO_FAULT 00 FAULT ALARM OVER TEMP 01 Internal temperature too high FAULT ALARM CAL LIMIT 02 Input level for calibration exceeded limit FAULT ALARM TCM 04 Input level for TCM calibration exceeded limits FAULT ALARM CMD CHAR 08 Unprintable characters received cmd too long FAULT TXBUF SPACE 10 Low on space in transmit buffer FAULT ALARM TXBUF FULL 20 Serial transmitter buffer full FAULT ALARM RCVBUf FULL 40 Serial receiver buffer full FAULT ALARM NVRAM 80 NV RAM fault Power on default 00 FAULT QUERY Returns the alarm bit mapp
5. command Must send all 5 digits with leading zeroes Power on default Depends on range Chapter 6 Remote Operations RS 232 Interface HLCHI QUERY Reads the Hi Lo Comparator high value from RAM for range Syntax HLCHI Response Floating fixed point Ohm value for current range 1 0000 for 10 in the 20 range and 100 00 for 100m0 in the 200m0 range This command reads the value from RAM memory only If you have used the HLCHI command to write a HLC value it will be different than the value stored in non volatile memory if the SAVSETUP command has not been sent Power on default Depends on range HLCLO COMMAND Sends the Hi Lo Comparator Low Limit for current range Syntax HLCLO lt value gt Where value 1 0000 for 10 in the 10 range 100 00 for 100mQ in the 100mQ range 1 000 for 1k in the 1kQ range This command writes the value to RAM memory only To store these values in non volatile memory follow with SAVSETUP Send RANGE command before sending this command Power on default Depends on range HLCLO QUERY Reads the Hi Lo Comparator low value from RAM for range Syntax HLCLO Response Floating fixed point Ohm value for current range 1 0000 for 10 in the 10 range and 100 00m for 100mQ in the 100m0 range 1 0000k for 1kQ in the 1kN range This command reads the value from RAM memory only If you have used the HLCLO command to write a HLC value it will be different than the value stored in non vol
6. The screen shows the display update rate UPDATE DISPLAY AS INTENSITY LEVEL 5 and intensity settings HLC The screen displays the HLC limits for the range that is selected at the time In this mode the user can switch through the ranges to view all the values set as limits RUH HOLD KEY RUN HOLD The screen will display the HUTTON AULD configuration of the RUN HOLD key PRINT MODE SET PRINT The screen will display the configuration of MO LUGE the PRINT LoG feature TEDE a TCM The screen will display the temperature FE Z B coefficient and temperature reference value set for the TCM mode CAL The screen displays the date of the last calibration This is update from the interface To exit the view function press VIEW 4300C User Manual OPTIONAL FEATURES AND ACCESSORIES OPTIONS The 4300C u Ohmmeters are shipped with a detachable power cord and an Operation Manual as standard equipment This section lists several items that may be desirable for special applications BCD Data Output GPIB USB ACCESSORIES This option provides parallel BCD data on a rear panel 50 pin connector All outputs are TTL compatible levels with a drive capability of 1 LS load Also refer to Chapter 6 Remote Operations BCD Interface The Valhalla 4300C comes standard with a RS 232 interface Also available is an optional GPIB IEEE 488 2 compatible interface The interface is talk
7. When connecting the cables to the inductive load care should be taken not to draw an arc The Test Current should be turned Off and the cables positively clamped onto the load before applying current When measuring highly inductive loads the settling time of the ohmmeter is determined by the compliance voltage of the current source Typically the compliance voltage of a 4300C in the Charging Inductor mode is in excess of 20V Thus with an inductor of 1000 Henries an extremely large transformer the unit will take approximately 10 minutes to settle During settling the unit will display overload and should be ignored until the Charging Inductor indicator is extinguished The actual equation for determining settling time is as follows T LxI V Where T settling time in seconds L inductance in Henries current range in amps V compliance voltage of 4300C 20V Note that the higher the test current the longer the settling time 9 1 4300C User Manual Noisy READINGS When measuring very low resistances of highly inductive loads care should be taken to reduce 60Hz pickup at the input to the 4300C The noise pickup is caused by the very high impedance of the load at 60Hz given by the formula Z 377xL Where Z Impedance in ohms L Inductance in Henries Thus with a 1000 Henry transformer the impedance at 60Hz would be 377Kohm across which many millivolts of noise may be induced by movement or by interfe
8. e Charging Inductor mode for reduced settling times e Disconnect Status indicators designed with safety in mind e Full 4 wire Kelvin terminal configuration e Fully selectable test currents up to 10A e Temperature Compensation e Internal Hi Lo Limit Comparator e Available locking rear Bendix connectors e Available data outputs and remote programming capability Please read this manual thoroughly and all accompanying addendums before attempting to operate this ohmmeter 1 1 4300C User Manual INITIAL INSPECTION If the shipping carton is damaged request that the carrier s agent be present when the unit is unpacked If the instrument appears damaged the carrier s agent should authorize repairs before the unit is returned to the factory Even if the instrument appears undamaged it may have suffered internal damage in transit that may not be evident until the unit is operated or tested to verify conformance with its specifications If the unit fails to operate or fails to meet the performance specifications of Chapter 2 notify the carrier s agent and the nearest Valhalla Sales Office Retain the shipping carton for the carrier s inspection DO NOT return equipment to Valhalla Scientific Inc or any of its sales offices prior to obtaining authorization to do so BCD J 2Z Connectors l T Line Power oe E der d I K o re d Ss hy Sen ra I 1 rey fei x Kg d EE alm o USB Connector Fuse Ho
9. U17 is a digital switch that allows the micro controller to send data to the display or to the RS 232 port U16 is a RS 232 Driver Receiver This component converts data to the RS 232 level Refer to schematic 834u 070 sheet 6 TROUBLESHOOTING Apparent malfunctions are often the result of misinterpretation of specifications or due to an incomplete understanding of the instrument A thorough review of the operating instructions for this instrument is recommended prior to any component replacement etc Check to be sure that cables and other test equipment are in good working order before attempting to troubleshoot the 4300C If the Model 4300C exhibits problems that cannot be eliminated by reviewing chapters 2 3 4 6 7 or 9 the following guidelines have been established to help solve the problem Localizing the Problem The key to successful troubleshooting is to localize the problem as much as possible before trying to pin the problem down to a specific component Certain questions should be asked such as Does the problem occur on all ranges or on a specific range only The power supplies are also one of the first things that should be checked As it is not possible to anticipate all failure modes of the 4300C servicing personnel should become familiar with this chapter to gain a complete understanding of the internal workings of this instrument Chapter 7 Theory of Operations Component Replacement If the problem has been id
10. euranunrnnrnnnnnnnnnnnnnrnnvnnnnnnnnnnnnnnnvnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnennnsnnnnsee 11 5 ASU0C DISPLAY PE BOARD ASSEMBLY E 11 8 4A 300C OUTPUT PC BOARD EE rada 11 9 eege TE une 12 1 ME E 12 1 CONTROLLER BOARD SCHEMATICS sisassivassnnssindonssdandsnwtcadgnasniwndonnediondonssdandunstdadgnaeaiwadonnedeedonesdaoiuaatcadsnns 12 2 OW GR 8340 2071 PG DOF EE 12 2 MSN EE 12 3 DWG 834U 071 PG 3 Of EEE 12 4 4300C MAIN BOARD SCHEMATICS asnernernarnnsnnsnnnrnnrnnrnnsnnsnnnsnnsnnsnnennnrnernnsnnsnnsnnennernernnsnnsnnennennennesnnsnnsnne 12 5 DWGH 4300C 070 PG loft 12 5 DWG 43000 070 PG 2 Of 2 sra ba 12 6 4A 300C DISPLAY BOARD SATS 12 7 DWG 4300C 071 PG EE 12 7 ME NET 12 8 List of Tables Table 1 Ranges Parameters and Accuracies EE 2 1 Table 2 Temperature Compensation Mode Accuracy rrrrrrrnnnnnnrrnnrnnnnrrnnrnnnnsrnnrnnnssennrnnnsssnnsnneee 2 1 Table 3 Range Selection Table 3 2 Table 4 Function Numerical Keys Description 3 4 TNS BNR 3 10 TREE PV EE 3 11 Table 7 Range Selection Table cccccsssssccssssssscccscsssscsccncessssccncesssscensesssssencesssssensesssseensess 3 14 Table e Setup RE CN 4 4 Table 9 HLC Truth NEE 4 7 Table 10 HLC Default LimitS rrerenrnnnnrrnnnrrnrnnrnrnnennnnvnnnnnnnrnnnnnnnnnnnnnnnnnnnnnnnnnnnnnvnnnnsnnnnnnnnunnnnnnsennne 4 7 Table 11 HLC Truth Table 4 8 Table 12 ASCII Character CCOO nn idad 6 5 Ee e E E NR O A 6 14 Table 14 RS 232 Connector Pin C
11. leads simply press one probe against one side of the surface of your load making sure that the surface of the probe is in o full contact with the surface of the load Press the second probe against the surface at the oppose side of your load making sure that the surface of the probe is in full contact with the surface of the load For hard to reach Figure 20 Dual Ky ees i e AV Needle type probes SE surfaces Valhalla Scientific offers three different sets of spring loaded dual needle probes that differentiate in overall size and distance between the needles If this is your choice of leads simply press both the needles of one probe against one end of the surface of your load press both needles of the second probe against the surface at the oppose end of your load 3 13 4300C User Manual TAKING STANDARD MEASUREMENTS To make a measurement select to proper range and engage the Test Current Always be sure to disengage the Test Current after each measurement or before disconnecting the load and or leads from the instrument Setting the Range Table 7 Range Selection Table a F S VOLTAGE d Figure 21 Voltage Setting a Q RANGE y Figure 22 Ohms Setting The 4300C has 3 voltage settings and 6 current ranges The combination of the two result in 16 possible resistance measurement ranges See table 7 Voltage Setting 20mV 200mV 2V 10A 1A 1A 10mA 1mA mA
12. reading as it is displayed on the ohmmeter s screen When configured for Log pressing the PRINT key continuously transmits the measurements at a rate equal to the display update rate Pressing the print key once again will terminate the transmission The measurements are transmitted in the same format in which they are displayed on the ohmmeter s screen When configured for Log pressing the PRINT key continuously transmits the measurements at a rate equal to the display update rate Pressing the print key once again will terminate the transmission The measurements are transmitted in engineering format For example 10 000kQ 1 00E 04 See Display Update Rate page 4 8 4300C User Manual Configuring the Print button function To configure the Print Log function FUNC RUN HOLD KE 4 e Press FUNC PRINT e Select one of the three options by pressing keys 1 2 or 3 and press ENTER STORE IM HEI SETUP e The screen will display a brief message the selection is DATA IH HOURAM stored in memory and the instrument automatically returns to the previous mode Chapter 4 Measurement Modes and Functions VIEW FUNCTION The View function allows the user to view how the instrument s functions are configured This function is easy to use and is very useful especially for HLC and TCM users Using the View function Press View followed by one of the following keys UPDATE
13. 0 1 1 0 0 1 1 NUMBER 5 1 0 1 0 1 0 1 4 3 2 1 MSG ASCII MSG MSG MSG ASCII ASCII 0 0 0 0 NUL DEL 00 0 16 Q 00 P 16 p 0 0 0 0 1 SOH GTI DC1 LLO 01 1 17 A 01 Q 17 a q 1 0 0 1 0 STX DC2 02 2 18 B 02 R 18 b r 2 0 0 1 1 ETX DC3 03 3 19 C 03 S 19 c S 3 0 1 0 0 EOT SDC DC4 DCI 04 4 20 D 04 T 20 d t 4 0 1 0 1 ENQ PCC NAK PPU 05 5 21 E 05 U 21 e u 5 0 1 1 0 ACK SYN amp 06 6 22 F 06 V 22 f vV 6 0 1 1 1 BEL ETB 07 7 23 G 07 W 23 g W 7 1 0 0 0 BS GET CAN SPE 08 8 24 H 08 X 24 h X 8 1 0 0 1 HT TCT EM SPD 09 9 25 09 Y 25 i y 9 1 0 1 0 LF SUB 10 26 J 10 Z 26 j Z 10 1 1 0 0 FF PS 12 lt 28 L 12 28 12 1 1 0 1 CR GS 13 29 13 29 13 1 1 1 1 SI US 15 UNL 15 i UNT DEL 15 ADDRESSED UNIVERSAL LISTEN TALK COMMAND COMMAND ADDRESS ADDRESS GROUP GROUP GROUP GROUP ACG UCG LAG TAG PRIMARY COMMAND GROUP SECONDARY COMMAND GROUP PCG SCG Table 12 ASCII Character Codes Notes 1 Devices Address messages shown in decimal 2 Messages codes are DCI Device Clear LLO Local Lockout SDC Selected Device Clear GET Device Trigger PPC Parallel Poll Configure SPD Serial Poll Disable GTI Go to Local PPU Parallel Poll Unconfigure SPE Serial Port Enable Note that the table is divided into two main groups the primary command group and the secondary command group The secondary command group is not utilized in the 4300C t Requires Secondary Command 4300C User Manual The primary command group is further divided into four subgro
14. 1 4 DAE Yr e le E 1 5 CHAPTER Z SPECIFICATION VK 2 1 STANDARD MEASUREMENT MODE SPECIFICATIONS 2ccecceceeceecsececcecsecsececcececsecsecuceecsessececeecsesseeeeeeceesess 2 1 TEMPERATURE COMPENSATOR MODE SPECIFICATIONS snernernrnnrnnrnnvnnvnnrnennsnnsnnvnnnnsnnsnnennenennsnnennnnennsnnsnnenenn 2 1 GENERAL SPECIFICATIONS seede ER 2 2 ENVIRONMENTA Lascano oa 2 2 POWER REQUIREMENTS siria 2 2 ee EE 2 2 CHAPTER 9 GETTING STARVED BE 3 1 ee a O e e PO o POE E E 3 1 NON 3 1 PAP ER EE sat eee A 3 2 Range Selection and Test Current Key 3 2 Range Selection rrrrnnnnnrrnnrnnnnrnnnnnnnrrnnnnnnrsrnnnnnsssnnnnnssernnnnnssrnnnnnssrnnnnnnsssnnnnnsssennnnssssnnnnnee 3 2 TENNE 3 3 Eeer deed 3 3 TC Mode Key and Eegen eet 3 5 VEN 3 5 Cable Disconnect Status Inodicotors 3 6 NN nad 3 6 Source and Sense Binding Post 3 6 KEN EEE EEE EE e o NERE 3 8 Line votoge NNN 3 8 Fre 3 9 FM 3 9 HLC Relay e e 3 9 MN 3 10 NOV 3 11 POWER ON DEFAULT TINO Sears 3 11 CONNECTING ONE 3 12 TAKING STANDARD MEASUREMENTS ccoccoccccnccoccnnoncononcnnnonconronnnoronrnnonnnnnonrnnrnnrnronnnnrnnnnnennnnrnnrnnencnanonnnnos 3 14 NNN 3 14 PN 3 14 charging Inauctor Mode vesen 3 15 Cable Disconnect Status Inodicotors 3 15 CHAPTER 4 MEASUREMENT MODES AND FUNCTIONS sessesesessssecessscecessececessececesescecessececesososceseececesesoscesescecesee 4 1 STANDARD MEASUREMENT MOE rv 4 1 TCM TEMPERATURE COMPENSATED MEASUREMENT Mont 4 1 Ge EG JE SSE
15. 10 100 1000 1kO 10kQ 2 DC voltage standard capable of outputting 10mV 300mV 1V and 2V Valhalla Model 2701C is suitable for the task 3 Four wire test lead set 4 Precision Digital Voltmeter Note If this equipment is not available the ohmmeter may be returned to Valhalla Scientific for calibration traceable to NIST PRE CALIBRATION PROCEDURE The calibration adjustments are accessed by removing the top cover of the instrument The locations of the adjustment potentiometers are shown in Figure 42 at the end of the chapter Leave the cover in place as much as possible After each adjustment is made the cover should be replaced and the instrument allowed to stabilizing A ADANGER Dangerous AC line voltages exist inside the instrument Use caution when making adjustments to avoid contact with these voltages OR DEATH 8 1 4300C User Manual 4300C CALIBRATION PROCEDURE Standard Calibration The standard calibration consists of three parts sense calibration source calibration and final adjustment The sense calibration and the final adjustment calibration is cover on and automated the instrument will prompt the user throughout the steps The source calibration is performed by adjusting six potentiometers located on the 4300C main board All three calibrations must be performed for a complete calibration of the 4300C Sense Calibration Press the FUNC CAL CAL KEY OHMS CE D SS mar
16. 3 As 400msec 2 5 bs 500msec 2 Display Intensity The intensity of the display is broken DISPLAY INTENSITY Dim ss BRIGHT down into 8 levels where level 1 is the 1 2 3 4 5 6 7 8 least intense and level 8 is the most intense Chapter 4 Measurement Modes and Functions Setting the Display Update Rate and Intensity To change the display update rate and the display intensity FUNC i UPDATE Mn STORING MEW SETUP DATA IH HOLRAM Press FUNC UPDATE Select an update rate using the numerical keys from 1 thru 5 and press ENTER Select an intensity level using the numerical keys from 1 thru 8 and press ENTER The screen will display a brief message The values are stored in memory and the instrument automatically returns to the previous mode 4 9 4300C User Manual Function Window RUN HOLD FUNCTION The Run Hold function of the 4300C can be configured in three different ways RUN HOLD Figure 27 Display Function Window e When configured for Run Hold pressing the Run Hold key will freeze the readings on the display The function window displays HOLD To exit the hold state press RUN HOLD again the function window displays RUN RUN PKHI When configured for Run PeakHi pressing the Run HoLD key will activate the Peak Hi state the readings on the display will only increment therefore showing the maximum value measured The function win
17. 4300C is assumed to be at address 12 IO ENTER 712 A 20 PRINT A 50 GOTO 10 4O END The execution of this program results in a continuous display of the resistance measurement updated at the conversion rate of the instrument s A to D converter The result is returned in scientific notation in ohms As an example assume that the 4300C is in the 2V and 1mA ranges and the front panel display indicates 10567 which is 10 5670 The program above is executed The 4300C responds with the following number contained in AS 1 0567E 4 This is the measurement in scientific notation in ohms The E signifies a power of 10 or 10000 This means that the significant digits of the response should be multiplied by 10000 In another example assume that the 4300C is in the 20mV and 10A ranges and the front panel display indicates 1 9095 which is equal to 1 9095mQ The program is executed The 4300C responds with the following number contained in AS 1 9095E 3 This is the measurement in scientific notation in ohms The E signifies a power of 10 or 0 001 This means that the significant digits of the response should be multiplied by 0 001 An over range condition is indicated by 2 0000E Each response is terminated with an output data terminator which is used to signal the end of the transmission to the controller The default terminator is a g s carriage return and line feed The terminator may be changed us
18. 88 77 66 55 44 33 22 11 OO lt crlf gt FF EE DD CC BB AA 99 88 77 66 55 44 33 22 11 00 lt crlf gt FF EE DD CC BB AA 99 88 77 66 55 44 33 22 11 00 lt crlf gt a e BB AA 99 88 lt crlf gt Chapter 6 Remote Operations RS 232 Interface STB QUERY Returns the command status byte Syntax STB Response Command status number 0 OxFF Example STB lt crlf gt O1 lt crlf gt Fragment TCM ON lt crlf gt STB lt crlf gt TCM AFF lt crlf gt STB lt crlf gt returns ERROR 03 lt crlf gt TCM lt crlf gt ON lt crlf gt 0 CMD LAST COMPLETE 1 CMD UNKNOWN 2 CMD MISSING PARAM 4 CMD INVALID PARAM 8 CMD MODE OFF 16 CMD INCORRECT NUMBER PARAMS 32 64 128 CMD_CALLAREALPGMR Power on default 0 Note After a command or query with or without a response the STB query responds with hexadecimal number with bits mapped as above The STB query clears the command status byte as does any other correctly completed command The bits are sticky through the sending of the STB query response but are cleared after the data is transmitted 4300C User Manual TCM COMMAND Selects TCM mode on or off Syntax TCM lt ON or OFF gt Example TCM ON lt crlf gt TCM lt crlf gt ON lt crlf gt Power on default OFF TCM QUERY Responds with TCM mode on or off Syntax TCM Example TCM lt crlf gt ON lt crlf gt Response lt ON or OFF gt Power on default OFF Send this date after th
19. CES COMMAND TE 6 20 OPT OUERY AMP CU o 6 28 CNFG COMMAND cuisine 6 20 RANGE QUERY Lide 6 29 CINE GO orar 6 20 RONG QUERY aras 6 31 CURRENT RANGE COMMAND 6 29 RESET COM ND 6 31 CURRENT RANGE COMMANDS 6 30 SAVSETUP COMMAND AA 6 32 FAULT COMMAND comanda 6 21 SAVSETUP QUERY 6 32 FAULT QUERY EE 6 21 TEN 6 19 ALECOMMAND ge 6 22 TEM COMMAND suites 6 34 AE ER 6 22 TOM OUER EE 6 34 HLCHI COMMAND scsi cuts 6 22 TEST CURRENT COMMAND 6 30 AECHE OUER Vorrisiaieic eer 6 23 TEST CURRENT QUERY seeen 6 30 HLCLO COMMAND TEE 6 23 VOLTAGE RANGE COMMAND 6 28 e A 6 23 VOLTAGE RANGE QUERY ee 6 29 Chapter 6 Remote Operations RS 232 Interface SYST ERR QUERY Sends the System Error value to the remote host Cleared with CLS lt crlf gt Syntax SYST ERR Example SYST ERR lt crlf gt Response 1F lt crlf gt Power on default 0 BCD COMMAND Selects BCD mode on or off Syntax BCD lt ON or OFF gt Example BCD ON lt crlf gt BCD lt crlf gt ON lt crlf gt Power on default OFF Note BCD mode on puts the logic level BCD on the rear panel connector and the ranges on the relays outputs See the BCD Interface section of this chapter for BCD connector pin outs and relay descriptions BCD QUERY Responds with BCD mode on or off Syntax BCD Example BCD lt crlf gt ON lt crlf gt Response lt ON or OFF gt Power on default OFF 4300C User Manual
20. TCM ON first 9 LOG PENDING starts when user presses PRINT Power on default OFF 4300C User Manual OHMS QUERY Responds with reading from the front panel display and causes an immediate update of the conversion so repeated query requests gets most accurate data Send range command or AUTO prior to sending this to get the scaling factor The Ohms omega milli and kilo characters are removed during remote formatting Syntax OHMS Example OHMS lt crlf gt 20 000 lt crlf gt on 20m or 20k Ohm ranges Response lt 20 000 lt crlf gt gt Power on default 0 000 Note For Scientific notation Engineering format use RDNG OPT QUERY Returns the option text strings factory installed on meter from nonvolatile Syntax OPT Example OPT lt crlf gt Option s GPIB IEEE488 2 BCD PLC HLC TCM AUTO RS232 USB lt crlf gt VOLTAGE RANGE COMMAND Selects a voltage range Syntax VRANGE lt range number gt Range number 1 3 1 20mV 2 200mV 3 2V Chapter 6 Remote Operations RS 232 Interface CURRENT RANGE COMMAND Selects a current range Syntax IRANGE lt range number gt Range number 1 6 1 10A 4 10mA 2 1A 5 1mA 3 0 1A 6 0 1mA RANGE QUERY Returns the selected range Syntax RANGE Response Range number 1 18 1 RNG1 2 0000mQ 11 V3 10 RNG10 2 00002 I 4 V3 2 RNG2 20 000mQ 11 V2 11 RNG11 20 000Q 14 V2 3 RNG3 200 00mQ I1 V1 12 RNG12 200 00Q 14 V1 4 RNG4 20
21. Taine Il Press CAL to choose the standard calibration Y ZERO VOLTS EHTER OF CLEAR lll Apply a short between the Sense Hi and the Sense Lo binding post Once the short is applied press ENTER The ohmmeter will perform the zero calibration for all ranges Press CLEAR to return to the previous screen While zeroing the ranges the screen will display the following information Pass indicates the number of passing Range Under ADC Reading values that have been measured Gallbration 15 passing values must be measured before the timer reaches the 100 ER second limit for a successful tonne Lanas calibration IV When prompted by the display remove the short and apply 10mV to the sense terminals Press ENTER to continue or CLEAR to return to the zero cal screen While calibrating the ranges the screen will display the following information LAR BAD 8 2 Chapter 8 Routine Maintenance V When prompted by the display apply 300mV to the sense terminals Press ENTER to continue or CLEAR to return to the 10mV cal screen While calibrating the ranges the screen will display the following information VI When prompted by the display apply 2V to the sense terminals Press ENTER to continue or CLEAR to return to the 300mV cal screen While calibrating the ranges the screen will display the following information UF CLEAR When prompte
22. economical cost The screw type terminal allows connections to wires or spade lugs Contacts are rated at 100V 100mA Truth table of the contacts is listed in Table 9 Q s symbol represents the load measured value UL is the upper limit and LL is the lower limit set by the user Chapter 4 Measurement Modes and Functions Table 9 HLC Truth Table HLC State HLC Result XLO GO XHI ON LLE lt O lt UL OPEN CLOSED OPEN ON O lt LL CLOSED OPEN OPEN ON UL lt Q OPEN OPEN CLOSED OFF X OPEN OPEN OPEN OFF X OPEN OPEN OPEN OFF X OPEN OPEN OPEN Setting the Limits Each range has a different set of limits that can be programmed by the user Table 10 lists the default values programmed for each range Once the user sets new values the default settings will be overwritten and the user Settings will be stored in memory Table 10 HLC Default Range Lower Limit Upper Limit Limits 2m0 1 0000m0 2 0000mQ 20mQ 10 000mQ 20 000mQ 200mQ 100 00m0 200 00mQ 20 1 00000 2 00000 200 10 0000 20 0000 2000 100 000 200 000 2kQ 1 0000kQ 2 0000kQ 20kQ 10 000kQ 20 000kQ To set your custom readings simply select the range that better fits your load and follow this procedure FUNC HLC e Press Func HLC to bring up the first input screen INPUT ALO Pia e Using the numeric keys input a value for the upper limit Use CLEAR as a backspace to correct errors e Press ENTER to continue C MIH VALDE e Using the numeric keys input a v
23. first disconnect the Ohmmeter s power cord Insert one end of the fuse into the fuse cap Insert the fuse cap into the fuse holder With a small flathead screwdriver push in on the fuse cap and rotate it clockwise Replace blown fuses with their exact equivalent only Power Connector The 3 prong power connector on the rear panel of the ohmmeter is for the application of AC power to the instrument The mating power cord is included with the instrument at time of purchase Refer to Chapter 1 for available voltages and safety precautions HLC Relay Terminal The HLC relay terminal is internally RE TT wired to three relays which are active XLO GO XHI only when the HLC mode is selected According to the result of the comparison one of the relays will have its contacts closed while the remaining two relays will have contacts open The standard relay contact closure feature allows an automated sorting process to be set up at an economical cost The screw type terminal allows connections to wires or spade lugs Contacts are rated at 100V 100mA The truth table of the contacts is located in Chapter 4 4300C User Manual RS 232 Connector The RS 232 serial interfacing is done through the 9 pin female D Sub connector located on the rear panel of the instrument Knowledge of the specific pin functions of the serial connector may be necessary for certain applications Table 5 lists the pin assignment for the RS 232 connector a 5
24. is being measured a potentially lethal back SALE EMF is induced when the test current is removed The 4300C provides a discharge path for this back EMF and monitors the voltage The SAFE LED is illuminated when the back EMF is less than five CHARGING o volts INDUCTOR Figure 11 Disconnect Although the 4300C is protected against up to 500 Status amp Charging Amps of inductive kickback advisable to remove test leads with the Test Current On or with the UNSAFE LED lit In some extreme applications if leads are Inductor LEDs it IS not removed or pull loose before the SAFE LED is lit damage may occur to the 4300C and or injury to the operator The UNSAFE LED is also illuminated whenever a test current of 1A or greater is selected and the Test Current is on regardless of the load Charging Inductor Mode The Charging Inductor mode LED indicates when the standard current source compliance voltage of 7V is exceeded In this situation the 4300C provides a booster shot in excess of 20V to reduce the settling time when a large inductive load is being measured The display readings should be ignored when this LED is illuminated Source and Sense Binding Post Connections to the 4300C are made via the front panel source sense terminals which consist of two red and two black heavy duty binding posts with gold plated brass contact material The posts can accept standard banana plugs wires up to 12 AWG or sp
25. listen and provides range and ohmmeter function control Also refer to Chapter 6 Remote Operations IEEE Interface Another interface that is available is USB The interface is talk listen and provides range and ohmmeter function control Drivers are provided Omni Compensator To be able to use the TCM feature of the 4300C the user will need an Omni Compensator temperature sensor This item allows the ohmmeter to Feie de Onin Compensation compensate for temperature variations when testing any material Option RX 3 Rack Mount Adapter The 4300C u ohmmeters may be mounted in a standard 19 equipment rack using a set of optional rack ears Option RX 3 comes with all the necessary hardware for installation and mounting An assembly diagram on how to install to rack ears on to the instrument can be found in Chapter 1 5 1 4300C User Manual TEST LEADS This section details the different test lead sets and connectors available for use with the 4300C u ohmmeters All cables and test leads are manufactured by Valhalla Scientific Inc and are tested before shipping Alligator Clip Type Leads Option K Kelvin Lead Set Option K is a shielded 4 wire Kelvin cable set 48 inches in length terminated in gold plated alligator clips Option KCS Option K is the recommended general purpose lead set for most applications ee bredere Figure 29 K Kelvin Lead Set Option KCS Gold Plated Clips Option KCS
26. mode has been selected or A if TCM is enabled D reflects the present value of the output data terminator command C reflects the test current status U is the letter U if the 4300C senses that it is UNSAFE to disconnects cables an ASCII space character indicates SAFE H is the letter H if the 4300C s charging inductor mode has been activated an ASCII space character indicates no charging inductor F is the letter F if a fault is detected in the TCM sensing mode an ASCII space character indicates no faults 4300C User Manual Table 13 IEEE ASCII Commands CODE Cx Quick Reference vw for Error Ck W EOI S Selects hold mode Triggers single reading T Selects continuous reading mode N Selects normal mode TCM OFF A Selects TCM mode ON L Returns 4300C to Local E Configuration Status Word Query Q V I SND C UHF Chapter 6 Remote Operations RS 232 Interface RS 232 INTERFACE CONNECTING THE 4300C VIA RS232 INTERFACE The RS232 interface capabilities The RS232 interface provides a point to point connection between two items of equipment such as a computer and the 4300C There are some parameters you need to set on both sides Once you have set these parameters you can control the 4300C through the RS232 interface e Baud rate 9600 baud Parity bit none Data bit 8 bits Stop bit 1 stop bit Data flow control none Notes for RS232 installation The 4300C is a DCE Data Channel Equipmen
27. readings Operator error and fatigue are drastically reduced while significantly increasing testing efficiency A common application is receiving inspection of precision resistors by unskilled operators using the HLC mode If for example the resistors to be inspected and tested are 1 KN 0 1 the 4300C would be set on the 2kQ range the upper limit would be set at 1 0010kQ and the lower limit to 0 9990kQ If measured resistance is within these limits the GREEN indicator will remain illuminated indicating a within tolerance condition If either RED or the YELLOW indicator is illuminated that respective limit has been exceeded and the test sample should be rejected HLC Relay Terminal Figure 26 HLC Relay Pins BEEN The 4300C provides relay closure XLO GO XHI outputs which can be used to implement an automated batch sorting system for components or products operate counters sound alarms or shut off a process Resistors transformers strain gauges thermocouples and thermistors are a few items which could be individually toleranced in this manner for matching purposes The HLC relay terminal is internally wired to three relays which are active only when the HLC mode is selected According to the result of the comparison one of the relays will have its contacts closed while the remaining two relays will have contacts open The standard relay contact closure feature allows an automated sorting process to be set up at an
28. relay is ever energized at any one time Resistors R106 R108 R110 R112 and R114 along with potentiometers RV102 through RV105 are used to trim the shunts to produce a precise current output Protection Circuitry The protection circuitry is composed of diodes D101 D102 opto isolator IC102 A R123 and R124 The two diodes provide a discharge path for inductive loads D102 conducts when the back EMF from the load is greater than 5V which turns on the opto coupler through R123 and R124 This circuitry is used to determine the Disconnect Status LED condition Power Supply Relay RLA selects which secondary tap of transformer T1 is applied to the bridge rectifier composed of diodes D103 D106 Capacitor C101 levels the rectified AC voltage Relay RLA is controlled by the comparator circuit to provide a higher voltage to the output stage to reduce settling time when an inductive load is being charged Charging Inductor Mode The gate voltage of TR103 is compared to a reference voltage defined by D107 D109 When the gate voltage exceeds the reference voltage TR105 conducts which energizes relay RLA and opto coupler IC102 B Transistors TR104 and TR105 form a Schmidt trigger circuit to reduce relay chattering Buffer IC101 B isolates the gate drive circuit from the comparator to reduce rail injected noise Block Diagram Chapter 7 Theory of Operations Micro Controller Board Complete circuitry is shown on schematic 834u 071
29. resistance value to display utilizing the ambient temperature and other parameters that will be present in later chapters It is solemn for the user to be aware if the TCM mode is enabled or disabled so that the display reading may be interpreted correctly The green LED located within the TCM key is the visual indication that the TCM mode is on A Fault message on the display indicates a missing sensor or that the sensor is not properly inserted in the receptacle The TCM key is used to enable or disable the TCM mode This portion of the front panel is designated to give the user a visual indication of the HLC results HLC mode is described in detail in the next chapter The HLC LEDs are active only when the Hi Lo comparator mode HLC is in use The green LED labeled GO is on if the measured resistance value is between the limits set by the user The yellow LED labeled XLO is on if the measured resistance value is less than the lower limit The red LED labeled XHI is on if the measured resistance value is greater than the upper limit The Omni Compensator is an optional accessory to the 4300C See Chapter 4 3 for more detail See Chapter 4 8 for detail on how to set the Hi Lo limits 4300C User Manual Cable Disconnect Status Indicators The SAFE and UNSAFE LED s indicate whether or not it is safe to disconnect the test leads from the load We or from the instrument When a highly inductive L load
30. the remote available to the key press enthusiast This capability is not without restrictions Illegal key sequences may get the machine in a menu you do not expect or cause the meter to not process properly the keys you send Key presses are human interface and therefore not buffered Because of this key delays may be necessary as sending keys too quickly may lose keys 4300C User Manual KEY QUERY Returns the decimal number of the key last key processed by the state machine This query returns any key in the remote mode even if the key is locked out by remote mode i e KEY LOCAL is not locked out Syntax KEY lt crlf gt 21 lt crlf gt Response Decimal Key value between 0 24 O No key pressed 0 KEY NO KEY 19 KEY 1 1 KEY O 20 KEY RANGE 1 2 KEY 3 21 KEY 4 3 KEY CLEAR 22 KEY RANGE 0 4 KEY 9 23 KEY 7 5 KEY LOCAL 24 KEY RANGE 3 6 KEY RESET 7 KEY FUNC KEY UPDATE KEY 1 8 KEY ENTER KEY HLC KEY 2 9 KEY DP KEY ADDR KEY 3 10 KEY RANGE 4 KEY RUNHOLD KEY 4 11 KEY 2 KEY PRINT KEY 5 12 KEY RANGE 5 KEY TCM KEY 6 13 KEY 5 KEY AUTO RNG KEY 7 14 KEY RANGE 6 KEY CAL KEY 8 15 KEY 8 KEY BCD KEY 9 16 KEY 6 KEY VIEW KEY 0 17 KEY NOTUSED KEY DISPLAY KEY 1 18 KEY RANGE 2 KEY mk KEY DP Usage Keys are polled every 25ms in a timer interrupt This routine changes mode to local and responds with the last key pressed It can sense keys even in remote mode Keys are debounced but are not tested for each menu state In other words sending KEY 4 in a sta
31. tracking mode default S selects hold mode also used to trigger a single reading while holding Temperature Compensation The automatic temperature compensation mode TCM feature of the 4300C may be enabled or disabled from the GPIB If TCM mode is enabled the readings are automatically adjusted by the temperature sensor attached to the front of the 4300C refer to Chapter 4 N selects normal mode TCM off A selects TCM on Chapter 6 Remote Operations IEEE Interface Configuration Status Query This advanced command may be used to verify the results of sending the commands mentioned previously It may also be used to check for faults in the TCM system or to check the present setting of the manual controls on the front panel The charge and discharge of inductive loads may be monitored to determine when valid readings are available and also to check the cable disconnect status indicators Upon receiving the code E the 4300C will place into its output buffer a configuration status word The status word is made available for the next read by the controller No measurement data is available until this word is read The word is in the format Q V I SND C UHF Where Q reflects the present value of the SRQ command V reflects the present voltage range setting 1 reflects the present test current setting S is the letter S if hold mode has been selected or T if tracking mode is selected N is the letter N if normal
32. 000mQ 12 V3 13 RNG13 20 000Q 15 V3 5 RNG5 200 00mQ 12 V2 14 RNG14 200 00Q 15 V2 6 RNG6 2 0000Q 12 V1 15 RNG15 2 0000kQ 15 V1 7 RNG7 200 00mQ 13 V3 16 RNG16 200 00Q 16 V3 8 RNG8 2 0000Q 13 V2 17 RNG17 2 0000kQ 16 V2 9 RNG9 20 000Q 13 V1 18 RNG18 20 000kQ 16 V1 VOLTAGE RANGE QUERY Returns the selected voltage range Syntax VRANGE Response Range number 1 3 1 20mV 2 200mV 3 2V 4300C User Manual CURRENT RANGE COMMANDS Returns the selected current range Syntax IRANGE Response Range number 1 6 1 10A 4 10mA 2 1A 5 1mA 3 0 1A 6 0 1mA TEST CURRENT COMMAND Selects TEST CURRENT on or off Syntax TCURRENT lt ON or OFF gt Power on default OFF TEST CURRENT QUERY Responds with TEST CURRENT on or off Syntax TCURRENT Example TCURRENT lt crlf gt ON lt crlf gt Response lt ON or OFF gt Power on default OFF RDNG QUERY Chapter 6 Remote Operations RS 232 Interface Responds with reading from the device in engineering notation Query function also uses an immediate update of the conversion so repeated query requests gets the most accurate data Syntax Example Response RDNG RDNG lt crlf gt 2 4321e 1 lt crlf gt on 20 0000 ranges lt value in reduced engineering notation lt crlf gt gt Power on default 0 000e 0 CAUTION Will not work if the transmit interrupt happens to be busy with a display update and the foll
33. 0C User Manual Chapter 2 SPECIFICATIONS This section contains accuracy and operational specifications for the Model 4300C The accuracy specifications are valid for a period of one year from the date of calibration at a temperature of 22 C to 28 C Outside this range the temperature coefficient specification applies STANDARD MEASUREMENT MODE SPECIFICATIONS Range 1 2m0 2 20mQ 3 200m 4 20 5 200 6 2000 7 20mQ 8 200mQ 9 20 10 200 11 2000 12 2kQ 13 200m0 14 20 15 200 16 2000 17 2kQ 18 20kQ Test Voltage 20mV 20mV 20mV 20mV 20mV 20mV 200mV 200mV 200mV 200mV 200mV 200mV 2V 2V 2V 2V 2V 2V Full Scale 2 0000m0 20 000m0 200 00m0 2 00000 20 0000 200 000 20 000m0 200 00m0 2 00000 20 0000 200 000 2 0000kQ 200 00m0 2 00000 20 0000 200 000 2 0000kQ 20 000kQ Resolution 100n0 110 1010 10010 1mO 10m0 Lu 10uQ 100uQ 1mQ 10mQ 100m0 1010 10010 1mO 10m0 100m0 10 Table 1 Ranges Parameters and Accuracies Current Source 10A 1A 1A 10mA 1mA 1mA 10A 1A 1A 10mA 1mA mA 10A 1A 1A 10mA 1mA 1mA Accuracy of Reading 0 06 0006m 04 006m 04 06m 04 0006 04 006 04 Ip 06 003m 04 03m 04 0003 04 003 04 03 04 0013k 06 03m 04 0003 04 003 04 03 04 0003k 04 003k t t E TEMPERATURE COMPENSATOR MODE S
34. 20 e 1A 3 200m0 9 20 15 200 S 10mA 4 20 10 200 16 2000 5 1mA 5 200 11 2000 17 2kQ 9 ama 6 2000 12 2kQ 18 20kQ o The two keys labeled F S Voltage are used to change the voltage setting F S VoLtaGE The f key is used to increase the voltage setting and the Y key is used to L decrease the setting Figure 5 Voltage Setting 3 2 mm Q RANGE d Figure 6 Ohms Setting Chapter 3 Getting Started Within a voltage setting there are six possible Ohms Ranges The two keys labeled Q Range are used switch between the ranges The key is used to increase the range and the Y key is used to decrease the range As the Ohms range increases the current range decreases and vice versa Test Current Key The Test Current key is used to turn the current source ON and OFF A a TestCurrenr TEA LED within the Test Current key indicates the status of the current Figure 7 Test Current source The current source may also be turned on and off via a command from one of the interfaces or by a remote foot switch Option RS Function Numerical Keys Figure 8 Function Numerical Buttons There are sixteen Function Numerical keys which are used to trigger the standard and or optional ohmmeter functions and for data entry Figure 8 depicts the key arrangement while table 4 lists a brief description of the keys and their use The Remote Led indicates the remote local state of the instrument If the LED is
35. 33 MP 2 Mini Probes 0 18 spacing Single Pointed Probe Set Option MP S is a 48 inch shielded cable set with a 1A test current capacity employing a set of single pointed handheld pencil type probes 2 wires to each point 553 4300C User Manual Surface Probes Option MP 4 Surface Probes These probes permit rapid repeatable bonding testing on a variety of screened or flat surfaces Test current is evenly distributed through the probe base while sensing is accomplished via a spring loaded center contact The target area is 2 1 inch in diameter Option MP 5 Surface Probes These probes permit rapid repeatable bonding testing on a variety of screened or flat surfaces Test current is evenly distributed through the probe base while sensing is accomplished via a spring loaded center contact The target area is Figure 36 MP 5 Surface Probes inch in diameter Other Lead Sets Option BBL Banana to Banana Cable Option BBL is a 48 shielded cable terminated on both ends in dual stacking banana plugs This cable may be used for voltage and current connections to the ohmmeter Option SL 48 Low Thermal Leads Option SL 48 is a 48 shielded lead set terminated in gold plated spade lugs This lead set is designed to eliminate problems caused by thermal EMF s and is rated for the maximum output current of 1A Figure 37 SL 48 Low Thermal Leads 5 4 Chapter 6 RE
36. 4 10 eege eege 5 1 Figure 29 K Kelvin Lead Set avden 5 2 Figure 30 KK Heavy Duty Lead Set 5 2 Figure 31 C Banana Clip Cable cccccccccseseseeeseeeeeeeeeeeeceeeeeeeeeceeeeeeeeeeeeeeeeeeeceeeeeeeeeeeeeeees 5 2 Figure 32 MP 1 Micro ROT 5 3 RE MP2 Mini lee 5 3 Figure 34 MP S Single Pointed Probes 5 3 Figure eg VPT EP 5 4 Figure 36 MP 5 Surface Probes ccssssccssssssscccsesssscecccsssscccccsssscesccssessessesssssescesssssensesssscess 5 4 Figure 37 SL 48 Low Thermal Leade 5 4 Figure 38 4 Wire Confieuratton 7 1 Figure 39 4300C Block Diagram cccssssecccccessecceceeeeccecaesececceaeeeceesaeasecesseaaeeessegueeeeesageeeeees 7 2 Figure 40 Current Source Block Diagram rrrrnnnnnnnrrnrnnnnnrnnnnnnnnrrnnrnnnnnrnnnnnnnsrnnnnnnnsennnnnnessnnnnnnnseee 7 5 Figure 41 u Controller Block Diagram cccssssscssssssscccssssssccscsssscescessesccccessessescesssscensesssssess 7 7 Figure 42 gt Drawing N2oAS00C A 8 6 xii xiii INSPECTION amp INSTALLATION INTRODUCTION Welcome to the world of low resistance measurement The Model 4300C is a unique instrument capable of handling even the toughest resistance measurement applications The 4300C is designed to measure the low resistance of such items as coils transformers ballasts heater elements etc Some features of the 4300C that give it an edge over competitive products are
37. 4 Su ace een 5 4 Option MP5S Sul dace e 5 4 OEIC CG SOUS Hah 5 4 Option BBL Banana to Banana Cable utani n nani a 5 4 ege E Be TE den ERR EE 5 4 CHAPTER 6 REMOTE OPERATIONS RS 6 1 EEE NERE va 6 1 THE GET lgl Eh Nee 6 1 DENON ass 6 2 BUS D engel 6 3 EECHER 6 4 SETTING TE geet 6 7 ege Reie Enn EE 6 8 Pose 6 8 Remote Se arsenate vedanta AS 6 8 READING THE DISPLAY ATA bebe 6 8 A SOUC COMMANDO SET FOR PB vvs gees 6 10 VOGEL 6 10 Fetter EE 6 11 SRO S and SENG E 6 11 UG DOT 6 12 Test turen CONE OL sv SAGN den 6 12 DEPAY 9 GE EEE ERE EE EEE EE ER 6 12 temperature Compensa aaret se 6 12 EENHEETEN 6 13 RS 2 ZINE 6 15 CONNECTING THE 4300C VIA RS232 INTERFACE ssssnosnonssessessresssessesrrsesssrsersesseseesersessesseseeseesesse 6 15 TMERS232 JNCCIFACE COD CONICS SD 6 15 NOTES for RS232 Installation ass Ee 6 15 CONNECTING to d ef 6 16 CHECKING COMME CHONS EE 6 16 INPUTAND OUTPUT OWE Bie EE 6 17 COMMANDS ANDSYNTAX spa A 6 17 R9232 Message ee 6 17 Entering COMMONS ve 6 17 Commana Characters EE 6 17 COMOINTAOCOMNINAS He 6 17 Synopsis of Commands ii AA AA a ia a 6 17 DETAILS OFCOMMAND REFERENCE munnen eee 6 18 COMMANDIN DEX coreana T TOS E ASES 6 18 PD INE NE 6 35 GENER 6 35 BE DP PIN ASSIONMENTS Luse ee 6 35 DOT A EEE EEE SE NR EE EEE 6 35 RANG seder 6 36 Verona 6 36 PISOS INN CA vere 6 36 CHAPTER 7 THEORY OF OPERATIONS ee 7 1 TN RECON ION AT 7 1 GENERAL DESCRIPTION OF CIRCUITS vassere see GER 7 2 DE
38. A in 1V out 1A in 1V out etc The operation of the current source is as follows Current from the power supply flows through the load output stage and current shunt The voltage dropped across the shunt is compared to the reference voltage by the error amplifier The error amplifier uses the voltage drop across the internal shunt to control the amount of current passing through the load as necessary to maintain a precise constant current Protection Circuitry The protection circuitry protects the output stage from inductive kickback voltages The UNSAFE signal indicates the presence of back EMF from the load 4300C User Manual o Micro Controller Board 834u 701 This is the central processing unit of the ohmmeter The analog to digital conversion the range selection LED indicator selection and all other decision making processes occur in this portion of the instrument CPU The micro controller processes the data received by the ADC s and sends a ohms reading to the display Also from the data received from the keypad the micro controller selects the current range activates the LEDs and sends data out from the rs 232 port ADC The micro controller s analog to digital converters sense the voltage drop across the load TCM ADC The micro controller s analog to digital converter sense the voltage across the temperature sensor Omni Compensator Current Range Selector The current range selection occurs
39. C103 along with resistors R116 R118 and RV101 form a temperature stabilized voltage reference IC103 is a precision 4 1V precision reference LM4140ACM The zener current is limited by resistor R116 A voltage divider composed of R117 RV101 and R118 divide the zener voltage down to 1 0000 VDC Capacitor C103 removes any noise riding on the reference output Error Amplifier The error amplifier is composed of C102 IC101A R104 R103 RLB 2 and TR103 IC101A provides high DC gain to drive transistor TR103 via resistors R104 and R103 C102 provides local AC feedback around IC101A for stability TR103 provides base current to the output stage Relay contact RLB 2 is closed when the test current is turned off which removes the gate drive to TR103 7 5 4300C User Manual Output Stage The output stage composed of TR101 TR102 R101 R102 R126 and RLB 1 provides current gain capable of sourcing 10 amps Base drive for transistors TR101 and TR102 is provided by the error amplifier Resistors R101 and R102 equalize the emitter currents in the two output devices Relay contact RLB 1 is closed when the test current is turned off which connects resistor R126 across the output terminals to reduce the output voltage to less than 20mV Range Switching Range selection is accomplished by selecting one of the precision current shunts R105 R107 R109 R111 R113 or R115 Relays RLC thru RLH select the appropriate combination of shunts Only one range
40. MOTE OPERATIONS IEEE INTERFACE THE PURPOSE OF IEEE STANDARD 488 The purpose of the IEEE Standard 488 is to allow for interconnection of programmable instruments with minimum engineering The intent is to remove the need for adapters and the numerous types of patching cables often encountered with other forms of interfaces The IEEE 488 standard defines a system configuration for programmable instruments such as calculators voltmeters and other types of peripheral devices produced by various manufacturers It provides a set of rules for establishing defined communication links with a high degree of compatibility yet maintaining flexibility between independently manufactured products 6 1 4300C User Manual DEFINITIONS Listed below are definitions of the terms used to describe the IEEE 488 interface Bus A data link which is usually a set of several parallel wires within a multi wire cable Bi Directional Bus A highway used for two way communication with input and output data being carried on the same lines Bit Parallel A data transmission method in which all of the bits composing an item of data are present simultaneously on a group of wires in a bus Byte A group of eight data bits which is treated as a single item of data Byte Serial A data transmission method in which information in bit parallel bytes is transferred sequentially between devices Device Dependent Message A message containing commands or dat
41. Operations o 4300C Main Board 4300C 700 This portion of the ohmmeter contains the power supply and the constant current source e Power Supply This section converts the AC line power into the DC levels necessary to power the ohmmeter s circuitry e Constant Current Source This section of the main board provides a stable test current that is passed through the load to develop a voltage across it The value of this current for each range is indicated on the front panel of the instrument Current Source Reference The current source reference voltage is provided by an internally opened zener reference and its associated components The reference circuit provides a 1 0000 volt output to the error amplifier circuit Error Amplifier The error amplifier compares the reference voltage with the signal from the range switching circuit to drive the output stage The ON OFF signal from the control logic commands the error amplifier to turn on or off the output stage Output Stage The output stage provides current gain capable of driving 10 amps into the unknown resistance The ON OFF signal from the control logic disables the current source output when the test current is turned off Range Switching The range switching circuits provide six ranges of precision current shunts to control the output current The current shunt values are selected so that 1V is dropped across the shunt for each current range e g 10
42. PECIFICATIONS Accuracy Range Range Settings of Reading 0 Range Range Settings 1 2m 10A 20mV 11 0006m 10 20 10mA 200mV 2 20m 1A 20mV 09 006m 11 200 1mA 200mV 3 200m 1A 20mV 09 06m 12 2k 1mA 200mV 4 2 10mA 20mV 09 0006 13 200m 10A 2V 5 20 1mA 20mV 09 006 14 2 1A 2V 6 200 1mA 20mV 09 06 15 20 1A 2V 7 20m 10A 200mV 11 003m 16 200 10mA 2V 8 200m 1A 200mV 09 03m 17 2k 1mA 2V 9 2 1A 200mV 09 0003 18 20k 1mA 2V Table 2 Temperature Compensation Mode Accuracy 2 1 Temperature Current source is 1 Coefficient absolute accuracy 50ppm C 50ppm C Accuracy specifications 50ppm C are valid following a 30 50ppm C minute warm up at an 50ppm C ambient temperature 50ppm C between 22 C and 28 C 50ppm C and include the effects of 50ppm C line voltage variations 50ppm C within the allowed range 50ppm C 50ppm C 3 Temperature coefficient 50ppm C Specified for temperature 50ppm C ranges from 5 C to 21 C 50ppm C and 29 Cto50C 50ppm C 50ppm C 50ppm C 50ppm C Accuracy Accuracy of Reading 0 specifications valid 09 003 following a 30 09 03 minute warm up at 09 0003k an ambient 11 03m temperature 09 0003 between 21 C and 09 003 29 C 09 03 09 0003k 09 003k 4300C User Manual GENERAL SPECIFICATIONS Rei EE Multi Section VFD 140px x 32px Overl
43. RET 4 3 MN 4 3 1Go Temperature ei Ee e EE 4 3 TCC Temperature Compensator Calibration o ooooococcccoonnonnnnoonnonnnnnnanonononnnaronnos 4 5 AEG HO COMPARATOR le KT 4 6 PEG Relay Terminal E 4 6 vill A EE E a S 4 8 UPDATE FUNCTION EE 4 8 Display Update e 4 8 DIS DIG TENS TV EE 4 8 Setting the Display Update Rate and Intensity ocoooccccccononoconnnnonanonncnanonononononenanononos 4 9 RON FORD FINT ON 4 10 NON 4 10 RON PA bare 4 10 NONE 4 10 Configuring the Run Hold FUN cia 4 10 PRINT LOG FUNCTION NEEN 4 11 PRINT ad 4 11 GN 4 11 EE 4 11 Configuring the Print button function 4 12 VIEW FUNCTION vr 4 13 USING the View eet e EE 4 13 CHAPTER 5 OPTIONAL FEATURES AND ACCESSORIES sessssesescscesescscesescscesessecesescscesescscesescscesessscesescscesescscesee 5 1 OG EE EN RE ER AE EN REE EE EE EE EE EN NE ERR 5 1 BED DA OD ee 5 1 PENN 5 1 GE EE EE REE ABET See Een ee EEE EEE 5 1 ACCESSORIES vr 5 1 OMNECOND CHS OO A ee RT 5 1 Option RX 3 Rack Mount ee 5 1 ESTRENOS E 5 2 AMOO Fr CUD TV DC LENS an 5 2 Option ken lead E EE 5 2 Option KK Heavy Duty Lead Set 5 2 Option Banana ee We RECH EE 5 2 Needle TYDE EE 5 3 Option MP 1 Kelvin Micro PrODES sia gege ed aici E EES 5 3 Option MP 2 Kelvin Mini Probes rrrrrrrrnnnnnnrrnnnnnnrrnnnnnnrrnnnnnnersnnnnnnsrnnnnnsssnnnnnsssnnnnnsssnennn 5 3 Option MP S Single Pointed Probe Get 5 3 SUIC PODES ee Eegen 5 4 Option AWIP
44. TAILED CIRCUIT DESCRIPTION E 7 5 TT SE A EE 7 5 Ree 7 5 FO STE re 7 5 CUTOUTS tI vvs Se 7 6 MENE 7 6 Protection CCU ee 7 6 POWER ele Vista lid 7 6 Chareine nductor Modera si iia 7 6 Microcontroller BORO EE 7 7 Micro Controller aa NN 7 7 Over Voltage ege DE 7 7 TEN 7 7 Z SN REGENT 7 8 RS 232 Display Switch and RS 232 Driver Receiver ccccccccccccccccccecececceceeeeeceeeeseeeeeeeess 7 8 TROUBLESHOOTING ee 1 8 EOGOIIZING th PLO DION EE 7 8 Component Replacements EE 7 9 CHAPTER 8 ROUTINE MAINTENANCE sonia died 8 1 ENEE 8 1 REQUIRED TEST EQUIPMENT sp Ree 8 1 PRE CALIBRA TION PROCEDURE ae Ne 8 1 4300C CALIBRATION DROCEDURE nro ran r nr anno narrar nn r ora nr nnnnnnnannnnannnnannnnos 8 2 Standard e 8 2 SENSE CONDON ib 8 2 NNN NN 8 3 Reference Adjustment erisir Gases 8 3 10 Amp AGJUSUMBENE Luse obssesnsencsennsawoseendeassvasanwarvasaensauasauesabaseuns EE S ORN NESTES EN TENKA 8 4 ge AQ ASTON E 8 4 IA NE EE 8 4 TOMA AN US TRG ME E 8 4 TAAU MEA a 8 4 0 1mA Adjustment rrrrrronnornnnnnnrrnnnnnnrrnnnnnnnsrnnnnnnernnnnnssrnnnnnnsrnnnnnesennnnnnsssnnnnnsssnnnnnssssennn 8 4 FINN 8 5 CHAPTER 9 SPECIAL PROCEDURES Lee 9 1 GEER eegene 9 1 CONNECTIONS AND SETTLING TIME 9 1 NNN 9 2 DISCONNECTING THE CABLES hr 9 3 CHAPTER 10 ADDENDUM deenen eege eessen ege eege 10 1 CHAPTER LI KR EE 11 1 NID EX A A O o o A e Pi E EROS A A A E E A TEAT 11 1 uCONTROLLER PC BOARD ASSEMBLY iii ds 11 2 4300C MAIN PC BOARD ASSEMBLY
45. TING A LOAD TO THE 4300C Figure 18 Alligator Type clips The next step in using the ohmmeter is to connect to a load Valhalla Scientific Inc offers a number of different test leads that can be used with the Model 4300C and other Valhalla ohmmeter models see Chapter 5 for a list of available test leads All ohmmeter test leads are composed of a pair of leads both terminated in a multi stacking dual banana plug It is important to notice the position of the ground maker on the plug Marked side of each banana jack is connected to the source terminals e Connect the first lead between the SENCE HI and SOURCE HI terminals with the ground marker on the source side e Connect the second lead between the SENCE LO and SOURCE LO terminals with the ground marker on the source side This configuration ensures that current source is carried in the largest conductor of the cable and that the sense input is shielded The opposite end of the lead may vary in style of termination Here is a description of the three most common terminations used The most common termination is alligator type clips Figure 18 If this is your choice of leads simply connect one clip to one end of your load and the other clip to the opposite side of the load 3 12 Chapter 3 Getting Started Figure 19 Surface Type clips For flat surfaces you can use between two different spring loaded surface probes If this is your choice of
46. The controller waits for 2 seconds for settling then retrieves the measured value The 4300C is then returned to local mode Voltage Range The V command is used to set the full scale voltage range of the internal voltmeter The 4300C interprets this command as follows VO Selects the 20mV range V1 Selects the 200mV range V2 Selects the 2V range Chapter 6 Remote Operations IEEE Interface Test Current Range The I command sets the value of test current that will be used to make the resistance measurement The 4300C interprets this command as follows I0 Selects 1mA 11 Selects 1mA 12 Selects 10mA 13 Selects 1A 14 Selects 1A I5 Selects 10A SRQ s and Serial Polls The IEEE 488 bus incorporates a serial line that may be used by a device on the bus to alert the controller if problems are encountered or if it requires attention This method draws attention to a device without disrupting normal bus operation The controller may then choose to ignore or act upon the request The SRQ or service request line may be asserted to alert the controller The 4300C may be setup using the Q command to assert SRQ if the controller sends data to it that is not decodable by the 4300C QO 4300C will not assert SRQ default Q1 4300C will assert SRQ if it receives a command that it does not understand If the SRQ line is asserted the controller should then perform a serial poll to determine which device requ
47. a intended for a specific device Handshake An exchange of signals between two devices which is used to control the transfer of data between them Interface The part of an instrument or system which enables it to be connected to another via a bus Interface Message A message intended for interface management Local Operation Operation of a device by its front panel controls also referred to as Manual Control Remote Operation Operation of device under the control of another via the bus Chapter 6 Remote Operations IEEE Interface Bus RESTRICTIONS The IEEE 488 Interfacing Standard also known as IEC DTC66 WG3 ANSI MC1 1 GPIB HP IB etc defines a bidirectional bus for interconnecting programmable instrumentation in a bit parallel byte serial fashion It defines limitations as follows 1 A maximum of 15 devices may be interconnected by a single bus 2 The total bus length may not exceed 20 meters with a maximum interconnection length of 4 meters 3 Maximum transmission rate is 1 megabyte per second 4 All bus data is digital Of the devices on the bus only one may be the controller which exercises control over all other devices and is also capable of operating as a talker or listener The other devices may be listeners only able to receive data or talkers only able to send data or both The model 4300C is capable of talking and listening The controller may address other devices and command them
48. ade lugs The four Figure 12 Binding Post terminals provide full 4 Wire Kelvin measurement capability The right posts are the current source terminals and provide the test current while Chapter 3 Getting Started the left posts are the positive and negative voltage sense terminals used to monitor the voltage drop across the load When using Valhalla test leads the tabbed side of each banana jack is connected to the current terminals This ensures that current is carried in the largest conductor of the cable and that the voltage input is shielded O Ge x as n a 4 i b e y Fi 13 B PI Binding Post The 4 Wire configuration igure 13 Banana Plugs to Binding Pos eliminates errors normally caused by test lead and contact resistances In many applications the contact resistance can exceed the value of the load by several orders of magnitude The 4300C bypasses this potential error source by providing two terminals of constant current and an additional two terminals for high impedance voltage sensing The result is a fast accurate resistance measurement of the load independent of the resistance of the current carrying leads The Theory of Operation in Chapter 7 will illustrate how the 4 wire principle is used to eliminate lead wire and contact resistances as potential error sources 3 7 4300C User Manual REAR PANEL The rear panel of the 4300C may vary from unit to unit according to the optional fea
49. alue for the lower limit ril Use CLEAR as a backspace to correct errors 26ml 10A e Press ENTER to continue SAVE CAL VALUES e The screen will display a brief message and the instrument PRESS ENTER OR CLEAR will return to the standard measurement mode 4300C User Manual HLC ON To start working with the HLC mode simply select the correct range for your load and press the HLC The screen will briefly display HLC ON The instrument will also perform an LED check sequence Make sure that all three of the HLC LEDs illuminate After the LED check sequence only one of the three HLC LEDs will remain illuminated It is always good practice to check if the limits set for the range in use meet your specifications To view the set limits 0 yo 2 e press View HLC ie e The screen will display the both the upper and lower limit AOL set for that range dam 18A UPDATE FUNCTION The Update function is designed to allow the user to set the display update rate and the display intensity The user can choose from a list of five possible display update rates and eight levels of display intensities Display Update Rate The display update rate indicates the time interval in between every display update Table 11 lists these values and the equivalent in updates per second Table 11 HLC Truth Table Display Update Rate Display Updates second 1s 100msec 10 2S 200msec 5 3S 300msec 3
50. are gold plated alligator clips used on the Option K lead set for 4 wire measurements of smaller components and leads Clips open to 1 2 inch and accommodate test currents of up to 10A Option KK Heavy Duty Lead Set Option KK is a 4 wire Kelvin cable set 48 inches in length terminated in heavy duty gold plated clamps Option JA WS Option JAWS Gold Plated Clamps Option JAWS are gold plated heavy duty clamps used to terminate Option figure 30 Kk Heavy Duty Lead Set KK lead set Clamps open to 2 inches for connection to large motors bushings etc Option C Banana to Clip Cable Option C is a 48 general purpose shielded lead set terminated on one end in dual banana plugs and on the other end in red and black alligator clips Figure 31 C Banana Clip Cable 5 2 Chapter 5 Optional Features and Accessories Needle Type Probes Option MP 1 Option MP 2 Option MP S Kelvin Micro Probes Option MP 1 is a 48 inch shielded 4 wire Kelvin cable set with a 1A test current Capacity employing a set of Kelvin Micro Probes The probes are equipped with spring loaded stainless steel tips with u E Pens aal a M Figure 32 MP 1 Micro Probes Kelvin Mini Probes Option MP 2 is a 48 inch shielded 4 wire Kelvin cable set with a 1A test current capacity employing a set of Kelvin Mini Probes The probes are equipped with spring loaded stainless steel tips with Figure
51. atile memory if the SAVSETUP command has not been sent Send RANGE command before sending this command Power on default Depends on range 4300C User Manual IDN QUERY Returns the IEEE or RS 232 identification string from non volatile Syntax IDN lt crlf gt Response ID string VALHALLA SCIENTIFIC 4300C 1 01G 0 Example IDN lt crlf gt VALHALLA SCIENTIFIC 4300C 1 01G 0 lt crlf gt ID_STRING VALHALLA SCIENTIFIC VERSION gt 1 01G MODEL gt 4300C HARDWARE VER OI OPTION STRING Option s GPIB IEEE488 2 Chapter 6 Remote Operations RS 232 Interface KEY COMMAND Presses a key from the interface use for macros when the command you desire is not listed here Syntax KEY lt key number gt Response lt crif gt only after the key has been processed Key number 0 24 0 KEY_NO_KEY 19 KEY 1 1 KEY 0 20 KEY RANGE 1 2 KEY 3 21 KEY 4 3 KEY CLEAR 22 KEY RANGE 0 4 KEY 9 23 KEY 7 5 KEY LOCAL 24 KEY RANGE 3 6 KEY RESET 7 KEY FUNC KEY UPDATE KEY 1 8 KEY ENTER KEY HLC KEY 2 9 KEY DP KEY ADDR KEY 3 10 KEY RANGE 4 KEY RUNHOLD KEY 4 11 KEY 2 KEY PRINT KEY 5 12 KEY RANGE 5 KEY TCM KEY 6 13 KEY 5 KEY AUTO RNG KEY 7 14 KEY RANGE 6 KEY CAL KEY 8 15 KEY 8 KEY BCD KEY 9 16 KEY 6 KEY VIEW KEY 0 17 KEY NOTUSED KEY DISPLAY KEY 1 18 KEY RANGE 2 KEY mk KEY DP Power on default 0 Note The remote key macro command was developed so our customers can literally perform any action from
52. ating the full scale TCM the screen will display the following information When prompted by the display press ENTER to save the calibration values to memory or press CLEAR to return to the TCM full scale cal screen Connect an Omni Compensator to the TCM receptacle on the front panel Allow the sensor to settle for 2 3 minutes and press ENTER Using a precision thermometer record the ambient temperature Using the numerical keys enter the ambient temperature recorded in the previous step Press ENTER to continue Press ENTER to confirm the value or press CLEAR to return to the previous screen When prompted by the display press ENTER to save the TCM calibration values to memory or press CLEAR to return to the previous screen 4300C User Manual je el 3 Se ZOTAY 9OTAY SOTAY SG ee 90 e f Lef A LU NI ZEN Je IR al E AUT ai A d AN I Bar Di gt O j A VAY UC ki AVY NIFH 00 p H he Sa A A yuy i r H L j x o Drawing N Figure 42 4300C 700 Chapter 9 SPECIAL PROCEDURES GENERAL This section contains a number of useful tips that should be noted when working with inductive loads Inductive loads include devices such as transformers coils ballasts wire wound resistors magnets and motors These types of devices require special consideration as described below CONNECTIONS AND SETTLING TIME
53. d 3000ppmQA C AG25 25 C The following procedure illustrates how to select one of these configurations and how to setup a customized configuration This procedure does not need to be repeated every time the TCM mode is selected The configuration that is selected or the custom values inputted will be set as default FUNC TCM screen B ebe 2 Cues 3 5 e Press the number associated FLING configurations and press ENTER selection screen by pressing FUNC e Press the number associated configurations and press ENTER return to the previous screen e Press Func TCM 1 to bring up the first selection with one of the or go to the next with one of the or go to the next selection screen by pressing Func Press CLEAR to e Press 7 ENTER to enter the custom configuration screen Press CLEAR to return to the previous screen INPUT LOAD COEFF e Using the numeric keys input a value for the temperature SEET e Press ENTER to confirm the value coefficient Use CLEAR as a backspace to correct errors Gili dafir e Using the numeric keys input a value for the reference errors e Press ENTER to confirm the value temperature Use CLEAR as a backspace to correct Chapter 4 Measurement Modes and Functions e The screen will display the values entered e Press ENTER to confirm the values or CLEAR to
54. d by the display press ENTER to save the calibration values to memory or press CLEAR to return to the 2V cal screen When prompted by the display press ENTER to exit the calibration mode or press TCM to continue with the TCM Cal see Chapter 4 Current Source Calibration The following procedure should be performed when calibrating the current source section of the 4300C In all steps the current source is calibrated to the internal voltmeter therefore the sense calibration described earlier in the chapter should be performed before proceeding Alternately an external voltmeter of greater than 0 005 accuracy may be used Reference Adjustment This adjustment should only be performed if components in the reference section have been replaced and need not be performed on a routine basis A DC voltmeter with a minimum of 0 03 accuracy is needed to make the adjustment Connect the voltmeter low lead to OV front of R117 and the voltmeter high lead to IC101 pin 5 Adjust RV101 for 1 0000V Remove the voltmeter leads 4300C User Manual 10 Amp Adjustment Connect the 0 10 standard resistor to the 4300C using four wire connections Select the 2V and 10A ranges on the 4300C Adjust RV102 for a reading of 100 00m0 Allow extra time for settling in this range Keep the cover on as much as possible to ensure proper cooling of components 1 Amp Adjustment Connect the 10 standard resistor to the 4300C using four wi
55. ditional two terminals for high impedance voltage measurement The result is a fast accurate resistance measurement of the load independent of the resistance of the current carrying leads TCM TEMPERATURE COMPENSATED MEASUREMENT MODE Valhalla Engineers are pioneers in the technology of accurate measuring devices using recognized formulas that compensate for measurement inaccuracies as a result of environmental changes The TCM feature simulates a constant ambient temperature chamber for materials which are normally subject to varying ambient temperatures When in the TCM mode the temperature sensor Omni Compensator automatically senses the ambient temperature and compensates the reading to indicate what the actual resistance value should be in a controlled environment usually 20 C The compensated value is calculated with the following equation AR gAT FG 4 1 4300C User Manual The variation of resistance AR divided by the initial resistance Ro is equal to the temperature coefficient of the material a multiplied by the variation of temperature AT Expressed in terms of the resistance R R Ro a T T or R Ro 1 a T To To better understand our uses of the equation we will now express it in terms of our application Ry Rel1 a T Tr Where Rc is the compensated value Rm is the measured resistance Ta is the ambient temperature and Tr is the temperature reference Th
56. dow displays PKHI To exit the PKHI state press RUN HOLD again the function window displays RUN RUN PKLO When configured for Run PeakLo pressing the RUN HOLD key will activate the Peak Lo state the readings on the display will only decrease therefore showing the lowest value measured The function window displays PKLO To exit the PKLO state press RUN HOLD again the function window displays RUN Configuring the Run Hold Function To configure the Run Hold function FUNC RUN HOLD E e 4 e Press Func Run Hold FUM HOLD ACTION e Select one of the three options by pressing keys 1 2 or 3 LSHOL D ZSbRHI SR and press Enter ae al e The screen will display a brief message the selection is d UMP stored in memory and the instrument automatically returns to the previous mode Chapter 4 Measurement Modes and Functions PRINT LOG FUNCTION PRINT LOG LOG2 The Print Log function allows the user to receive the measurements through the instrument s RS 232 or USB interface A thermal printer labeler or the HyperTerminal of a PC can be used to capture the readings The measurements can also be log to an Excel spreadsheet by using a Data Sources Open Database Connectivity ODBC to access data from ohmmeter The Print Log function can be configured in three different ways When configured for Print pressing the PRINT key transmits one
57. e compensated resistance is therefore calculated as follows Rm EE OE 1 a T Tr The user can select from a list of temperature coefficients and temperature references The list is based on the most commonly used values The user can also customize these settings with unique values Once the temperature coefficient and the temperature reference are set the instrument s task is to measure the load resistance and the ambient temperature After all the variables are determined the 4300C automatically calculates the compensated resister value Here is an example of the equation Let s assume that we are measuring a copper wire and we wish to know the resistance value at a temperature of 20 C The temperature coefficient of copper is 0 0039310 C If the load measures 1 00000 and the ambient temperature is 22 5 C 1 Re 0 99030 1 0 003931 22 5 20 The value of the load at 20 C would be 0 099030 Chapter 4 Measurement Modes and Functions Omni Compensator TCM ON The 4300C measures the ambient Figure 24 Omni Compensator temperature through a removable ad external sensor the Omni Compensator This item does not come standard with the onmmeter and must be purchased separately If the 4300C and the Omni Compensator are purchased at the same time the pair will be calibrated together Each instrument should have a dedicated sensor The user cannot interchange se
58. e 17 BCD Pin Assignment Reference Table Chapter 7 THEORY OF OPERATIONS The information contained in this section describes the theory of operation behind the Valhalla Model 4300C Digital Micro Ohmmeter The theory is divided into two sections The first is a general description referring to the block diagrams of Figure 39 The second section is a detailed description referring to the schematics and diagrams at the back of this manual 4 WIRE CONFIGURATION Figure 38 on the LEAD RESISTANCE right illustrates how the 4 wire principle is Contact Resistance used to eliminate lead wire and contact resistances as potential error UO gt Or sources The internal Contact current source Resistance inherently overcomes all series resistance LEAD RESISTANCE within compliance voltage limits and Figure 38 4 Wire Configuration delivers a precise constant current The internal high impedance DVM senses the voltage drop across the load There is negligible contact and lead resistance error created by the voltage measurement because the high input impedance of the DVM limits current flow in the voltage leads 7 1 4300C User Manual GENERAL DESCRIPTION OF CIRCUITS This section describes the general function of each section of the Model 4300C The ohmmeter may be divided into four separate parts Figure 39 4300C Block Diagram Chapter 7 Theory of
59. e 4300C does not adhere to any friendly listening standards so the commands and queries must be typed as specified Command Characters The 4300Cs are not sensitive to the case of command characters You can enter commands in either uppercase or lowercase You can execute any command with preceding white space characters You must use at least one space between the parameter and the command header Subsequent parameters are separated by commas Combining Commands You can use a semicolon to combine commands but not queries Example RANGE 4 HLCHI 14 999 lt LF gt Synopsis of Commands The tables in this section summarize the commands of the programmable 4300C Ohmmeter 4300C User Manual DETAILS OF COMMAND REFERENCE Each command in this chapter will give a detailed description The examples of each command will be provided and what query form might return Syntax and return values for each are explained in the function header The STB gives the status of the command Remote mode is entered when a valid printable character is received and is exited with the LOCAL front panel key or LOCAL command COMMAND INDEX RST COMMAND cccccccceeessssesesssseeees 6 32 PN OUERT EE 6 24 SB QUERY sirere iee 6 33 KEY COVMIMAN Divisa aida 6 25 TT QUE e reee 6 34 Ker QUE sorna 6 26 BED COMMAND serian ais 6 19 LOCAL COMMAND sessi 6 27 BCD QUIER rn 6 19 LOG COMMANI AAA 6 27 CALDATE QUERY encantos 6 20 ORMS QUERY E 6 28
60. e calibration is complete followed by a SAVESETUP to store in EE memory TST QUERY Causes internal self test to run and returns the result Syntax TST Response Format hd CAUTION THIS FORMAT IS THE ONLY ACCEPTABLE BY IVI DRIVER BCD INTERFACE GENERAL Chapter 6 Remote Operations BCD Interface Option BCD provides parallel Binary Coded Decimal data output that corresponds to the display indication Signals are also provided for range information and overload A run hold line is also provided to halt the 4300C The signals are TTL compatible O lt 8V and 12 2 4V and will drive 1 LS TTL load BCD PIN ASSIGNMENTS Data Table 15 BCD Measurement Data Option BCD provides parallel Binary Coded Decimal data output that corresponds to the display indication Signals are also provided for range information and overload A run hold line is also provided to halt the 4300C The signals are TTL compatible 0 lt 8V and 12 2 4V and will drive 1 LS TTL load This is the BCD coded data which is identical to that being displayed by the 4300C 8 14000 9 110000 4300C User Manual Ranges This is a BCD exponent which indicates the present resistance range as follows Table 16 BCD Range Data Overload Pin 12 This pin is set to logic 1 when the data on the lines above is an overload indication Note The Data is arbitrary during this condition Pin assignment Tabl
61. ed byte Syntax FAULT Response 2 digit Hexadecimal number FAULT ALARM NO FAULT 00 FAULT ALARM OVER TEMP 01 Internal temperature too high FAULT ALARM CAL LIMIT 02 Input level for calibration exceeded limit FAULT ALARM TCM 04 Input level for TCM calibration exceeded limits FAULT ALARM CMD CHAR 08 Unprintable characters received cmd too long FAULT TXBUF SPACE 10 Low on space in transmit buffer FAULT ALARM TXBUF FULL 20 Serial transmitter buffer full FAULT ALARM RCVBUf FULL 40 Serial receiver buffer full FAULT ALARM NVRAM 80 NV RAM fault Power on default 00 4300C User Manual HLC COMMAND Selects HLC mode on or off Syntax HLC lt ON or OFF gt Example HLC ON lt crlf gt HLC lt crlf gt ON lt crlf gt Power on default OFF Note HLC mode on puts the logic level HLC relays on the rear panel connector and the ranges on the relays outputs See Chapter 4 for HLC relay contact descriptions HLC QUERY Responds with HLC mode on or off Syntax HLC Example HLC lt crlf gt ON lt crlf gt Response lt ON or OFF gt Power on default OFF HLCHI COMMAND Sends the Hi Lo Comparator High Limit for current range Syntax HLCHI lt value gt Where value 1 0000 for 10 in the 30 range and 100 00 for 100mQ in the 100mQ range and 00 500 for 5kQ in the 20kQ range This command writes the value to RAM memory only To store these values in non volatile memory follow with SAVSETUP Send RANGE command before sending this
62. entified as a faulty component the accuracy of the 4300C can be maintained only if the following precautions are taken Use only the specified component or its exact equivalent Spare parts can be ordered from your nearest Valhalla Scientific Service Center or from the factory directly by referring to the Valhalla Stock Number listed in the Parts Lists section at the back of this manual Use only 63 37 grade rosin core electronic grade solder with a 50W or lower maximum power soldering iron When soldering heat the terminal of the component not the solder Apply solder smoothly and evenly Do not move the component until the solder has cooled Bad solder joints can cause additional problems Static sensitive parts require special handling procedures Always treat an unknown part as if it were static sensitive 4300C User Manual Chapter 8 ROUTINE MAINTENANCE GENERAL This Chapter provides general maintenance information and a procedure for calibrating the ohmmeter The Model 4300C u ohmmeter should be calibrated on a routine basis every 12 months is recommended to ensure continued accuracy Before performing the calibration procedure below the ohmmeter should be allowed to warm up at a stable temperature for at least 30 minutes with the covers in place REQUIRED TEST EQUIPMENT The following equipment is required to perform calibration of the 4300C 1 Precision resistors within 0 005 the following values 0 10
63. h Warnings The following general safety precautions must be observed during all phases of operation service and repair of this product Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the product Valhalla Scientific assumes no liability for the customer s failure to comply with these requirements Ground the equipment For Safety class 1 equipment equipment having a protective earth terminal an interrupted safety earth ground must be provided from the main power source to the product input wiring terminals or supplied power cable DO NOT operate the product in an explosive atmosphere or in presence of flammable gases or fumes For continued protection replace the line fuse s only with fuse s of the same voltage and current rating and type DO NOT use repaired fuses or short circuited fuse holders Keep away from live circuits Operating personnel must not remove equipment covers or shields Procedures involving the removal of covers or shields are for the use of service trained personnel only Under certain conditions dangerous voltage may exist even with the equipment switched off To avoid dangerous electrical shock DO NOT perform procedures involving cover or shield removal unless you are qualified to do so DO NOT operate damaged equipment Whenever it is possible that the safety protection features built into t
64. his product have been impaired either through physical damage excessive moisture or any other reason REMOVE POWER and do not use the product until safe operation can be verified by service trained personnel If necessary return the product to Valhalla Scientific for service and repair to ensure that safety features are maintained DO NOT service or adjust alone Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT substitute parts or modify equipment Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the product Return the product to Valhalla Scientific for service and repair to ensure that safety features are maintained Measuring high voltage is always hazardous ALL multimeters input terminals both front and rear must be considered hazardous whenever inputs greater than 42V dc or peak are connected to ANY input terminal Permanent wiring of hazardous voltage or sources capable of delivering greater than 150VA should be labeled fused or in some other way protected against accidental bridging or equipment failure DO NOT leave measurement terminals energized when not in use Klatz GC Table of Contents CHAPTER 1 INSPECTION amp INSTALLATIO Nos ia 1 1 INTRODUCTION EEN 1 1 MENE 1 2 SETTING THE LINE VOLTAGE EE 1 3 FU E RE TION a A E E E E EE 1 3 KSSE EE
65. ing the D command Refer to Output Data Terminator section of this chapter 4300C User Manual 4300C COMMAND SET FOR GPIB This section contains a description of all commands that are recognized by the 4300C using it s IEEE 488 interface Option TL 488 As noted earlier in this chapter the 4300C does not need to be queried in order to retrieve the measured resistance data The commands listed in this section are used to set ranges turn the test current on and off and to setup internal communication protocol A condensed listing of the 4300C command set is given in Table 13 When sending commands to the 4300C an input data terminator must be used to signal the end of the command line The 4300C recognizes a _ carriage return or EOI asserted with the last character as valid input terminators Commands must be sent using upper case characters Multiple commands may be sent on the same line provided that they are separated by a comma The following program shows an example of setting the ranges of the 4300C The program is written in HP Basic If you are using a programming language or package other than HP Basic consult your Programmer s Manual for the correct command syntax The 4300C is assumed to be at address 12 IO REMOTE 712 20 OUTPUT 712 V2 15 CI 30 WAIT 2 40 ENTER 712 A 50 PRINT A 60 LOCAL 712 70 END The result of this program is to set the 4300C to the 2V 100mA ranges and turn on the test current
66. ion procedure The BCD key enables the binary coded decimal output on models where the BCD option is installed The CLEAR key functions like a backspace when entering values The key is also used to return to the previous screen The RESET key resets the ohmmeter returning it to Start Up state The LOCAL key is used to return from a remote to a local state The ENTER key is the user confirmation to a display prompt The Store key is used to store the active range as default Chapter 3 Getting Started TC Mode Key and Sensor Receptacle Figure 9 Temp Comp Mode Key and Receptacle HLC LEDs XLO GO Hi DIGITAL Limit COMPARATOR Figure 10 HLC LEDs Omni TEMPERATURE COMPENSATOR This portion of the front panel is utilized only during temperature TCM compensated type measurements TCM TCM mode is described in detail in the next chapter Critical to this measurement mode is precise temperature sensing which entails solid and reliable connections between the sensing device and the instrument The temperature sensor receptacle is designed so that the mating connector sensor the Valhalla Scientific Omni Compensator can be inserted only in the proper mating position A red dot on the Omni Compensator and a red tab on the receptacle are met to guide you in the insertion of the connector in the receptacle The TCM feature of the 4300C arithmetically calculates the
67. ires service The 4300C will return an ASCII zero 0 in response to a serial poll if it did not generate the SRQ A non zero number will be returned if it was responsible for asserting SRQ A serial poll is performed in HP Basic using the command SPOLL 712 which would poll the device at address 12 4300C User Manual Output Data Terminator The D command determines the type and quantity of terminators that will be used to signal the end of any data that the 4300C returns to the controller This includes measured resistance data as well as the response to the configuration status query The 4300C interprets this command as follows DO ae default D1 k r With EOI asserted D2 RE D3 er With EOI asserted The D1 selection is preferred by IEEE 488 2 systems such as National Instrumentse Test Current Control The C command is used to enable or disable the output of the current source This command is decoded as follows CO Turns the test current off C1 Turns the test current on Display Hold The display of the 4300C may be frozen from the GPIB bus using the commands listed below While in the hold mode the A to D converter is still performing measurements but the results are not sent to the 4300C s display or to the IEEE output buffer Therefore once a trigger is sent or tracking is resumed the display will instantly reflect the latest measurement The 4300C interprets these commands as follows T selects continuous
68. lder Option Line Voltage Switch Figure 1 Rear Panel Configuration 1 2 Chapter 1 Inspection Installation SETTING THE LINE VOLTAGE The line voltage selection is preconfigured according to the country to which it is shipped or as specified by the customer To change this setting follow the steps below 1 Remove the power cord from the instrument 2 With a small flat head screwdriver slide the Line Voltage Selector switch to the appropriate position 3 Replace the line power fuse accordingly Before connecting the device to an AC power source verify that the line voltage selection switch is set to match the AC line voltage and that the proper line fuse is CONDITION THAT COULD CAUSE DAMAGE TO EQUIPMENT installed These topics are discussed in the following sections FUSE SELECTION The line power fuse must match the line voltage selection as follows e 105 125VAC 3A SLO BLO e 210 250VAC 1 5A SLO BLO The fuse holder is located on the rear panel see Figure 1 To install a fuse first disconnect the Ohmmeter s power cord Insert one end of the fuse into the fuse cap Insert the fuse cap into the fuse holder With a small flathead screwdriver push in on the fuse cap and rotate it clockwise 4300C User Manual RACK MOUNTING Optional brackets are available for mounting the ohmmeter in a standard 19 equipment rack The rack mount kit consists of two brackets plus 4 flat head screw
69. ll enter the remote state Placing the instrument into remote is an easy way of verifying that all connections and address selections have been done properly This may be accomplished in HP Basic using the command REMOTE 712 The 4300C should enter the remote state and illuminate the REMOTE indicator Verify that no other device on the bus was affected by execution of this command READING THE DISPLAY DATA The resistance data on the 4300C s display is always available to be read by the system controller The 4300C does not require that a query or any other command be issued in order to retrieve it Also the 4300C does not need to be in REMOTE in order for the display to be read Retrieving the data will clear the reading buffer The controller must then wait until the next update of the A to D converter before a new value becomes available Data may be read at the rate of 2 readings per second for a 4300C The fact that the readings are always available simplifies measurement retrieval Every time the system controller polls the 4300C s address an instantaneous resistance value is returned corresponding to the displayed value The following program shows an example of retrieving a resistance measurement from the 4300C The program is written in HP Basic If you are using a programming language or package other than HP Basic consult your Chapter 6 Remote Operations IEEE Interface Programmer s Manual for the correct command syntax The
70. n on the computer Checking Connections If you want to test whether the RS232 connection is working or not YOU can send a command from the computer For instance using a terminal program send the query command idn Should return the Manufacturer model number serial number and firmware version in the following format VALHALLA SCIENTIFIC 4300C 1 81 0 If you do not receive a proper response from the 4300C please check if the power is on and all cable connections are active Chapter 6 Remote Operations RS 232 Interface INPUT AND OUTPUT QUEUE The design of 64 bytes input queue and 128 bytes output queue for storing the pending commands or return messages is to prevent the transmitted commands of remote control and return messages from missing As the maximum stored capacity for Error Event Queue is 20 groups of messages it should be noted that input data exceeding the capacity by using these buffers will cause data missing COMMANDS AND SYNTAX RS232 message terminators As there is no signal of end message on RS232 bus therefore use LF CR or CR LF as message terminator After the 4300C processes a command a CR LF is placed in the output buffer and delivered As for query command the return message of the instrument is also added a LF for PC to judge message terminator Entering Commands The standards that govern the command set for the 4300C allow for a certain amount of flexibility when you enter commands Th
71. nduced when the test current is removed The 4300C provides a discharge path for this back EMF and monitors the voltage The SAFE LED is illuminated when the back EMF is less than five volts Al A DANGER Although the 4300C is protected against up to 500A of inductive kickback it is not advisable to remove test leads with the Test Current On or with the UNSAFE LED lit In some extreme applications if leads are removed or pulled loose before the SAFE LED is lit damage may occur to the 4300C and or injury to the operator The UNSAFE LED is also illuminated whenever a test current of 1A or greater is selected and the Test Current is turned ON regardless of the load 4300C User Manual MEASUREMENT MODES AND FUNCTIONS The main characteristic of the 4300C is the 4 wire resistance measurements In addition to standard measurements the 4300C includes the TCM and HLC modes These features may significantly ease time and cost of temperature sensitive and automated selection applications STANDARD MEASUREMENT MODE In the standard measurement mode the instrument simply measures the value of the applied load using a 4 wire configuration This configuration eliminates errors normally caused by test lead and contact resistances In many applications the contact resistance can exceed the value of the load by several orders of magnitude The 4300C bypasses this potential error source by providing two terminals of constant current and an ad
72. nsors between different onmmeters without prior calibration Calibration will also be necessary if the sensor is purchased as a single item The TCM calibration routine is describe later in the chapter The TCM mode can be selected from the front TCM TCM panel by pressing the TCM function key LIE nn The display will briefly read TCM ON The instrument will continuously notify the user that the TCM mode is active by lighting the green LED within the TCM button If the TCM mode is turned ON without an Omni Compensator connected to the instrument the screen will displays SENSOR REMOVAL RESTART TCM SYSTEM Press TCM to turn the mode OFF Check if the Omni Compensator in properly connected to the front panel and turn TCM back ON To return to the standard measurement mode repress the TCM key The display will briefly read TCM OFF TCS Temperature Compensator Setup As earlier mentioned in this chapter the 4300C needs to reference a temperature coefficient and a temperature reference to calculate the compensated value Stored in the instruments memory are six configurations that can be selected Table 8 illustrates the values associated to each of the configurations 4 3 4300C User Manual Table 8 Material Contizurati n Temperature Temperature TCM Setup Ref Table B Coefficient Reference CU20 20 C 1 Q Copper SE 3931ppmQ C Ee AL20 20 C Alumi 4 Q uminum SEA 030ppmQ C 35 C AG20 20 C Gol
73. oad BR ln Le Ce EN Display flashes OVERLOAD FN Four wire Kelvin ADC Conversion Rate EE 45 conversions second Display Update 5 user selections 100msec 200msec 300msec 400msec 500msec Maximum Kick Back Protection cccccccccccccccceceeeesesssseeeeeeeeeeeeeeeeeeeaaaeeeesees 500A Peak Induced Current Compliance Voltage Normal Mode cccccccessseceeeeeseeceeeeeeeeceeseeeeeeeees 7 5 VDC nominal at 10A resistive Compliance Voltage Charging Inductor Mode cccccccceseseeeeeeeeseeeeeeeees gt 20 VDC when indicator is lit Open Circuit Voltage Test Current Off lt 20mV between IHI and ILO terminals ENVIRONMENTAL Operating Temperature Range ernernnnnennnvnnernnnnvnnnennenennnennnennenennnvnnnnennnennenennnennnennerennsennnennesenenene O to 50 C IN dia 70 RH at 40 C non condensing Storage Temperature EIERE EE dese 30 C to 70 POWER REQUIREMENTS Power NE sortida 105 125 or 210 250 VAC POWER SUBI Fe COLIC eege 50 60 Hz Power Supply Consumption ccccccccsssssecccceeseececceseceeseeeseceesseesseeessaeseseessaaaeeeessaaeeeeees 200VA Maximum PHYSICAL Bly En Se EN ole eicntacicoa 17 43cm W x 17 43cm D x 4 10cm H Ve 9 1Kg 20 Ibs Net 11 8Kg 26 lbs Shipping Chapter 3 GETTING STARTED Chapter 3 covers the fundamentals of ohmmeter operation This chapter will demonstrate how to use the ohmmeter s front amp rear panel how to make connections and also describes the display secti
74. on the instrument is in remote state and can only receive commands through one of its remote interface ports If the LED is off the ohmmeter is in local state will receive commands only from the front panel keys UPDATE ES LOCAL RUN HOLD PRINT CLEAR wae FUNC mo VIEW RESET ENTER aan 3 3 4300C User Manual Table 4 Function Numerical Keys Description Key Func View Update HLC Addr Run Hold Print Cal BCD Clear Reset Local Enter Store 0 INID U Description The Func key is used in combination with other keys to change stored settings This key is also used as a Forward key to skip through screens The View key is used in combination with other function keys It is used to view stored settings The UPDATE key is used to set and or view display update rate and intensity The HLC key is used to enable or disable the 4300C s internal Multi Range Dual Limit Comparator Also used to set and or view the limits used The Appr key is used to view the setting information for all of the standard or optional remote interfaces The RUN HOLb key is used to switch between run and hold state Also used to select the hold configuration The PRINT key is used to trigger the output of a print or log package to the RS 232 port Also used to select the print log setting The CAL key is used to initiate the standard and TCM calibrat
75. onfiguration rrrrnnnnnrrnrnnnnnrnnrnnnnnrnnrnnnnnrrnrnnnserrnrnnnesrrnsnneee 6 16 XI Table 15 BCD Measurement Data 6 33 ET e he RER 6 34 Table 17 BCD Pin Assignment Reference Table 6 34 List of Figures Figure 1 Rear Panel Configuration osonder 1 2 Figure 2 Rack Mount Kit eseorrorrorvervornorvernnnnevvennnnnnvvevnnnnnnvenennnvnsvvennevnsvvennevnsvvennevnsvvennavnesvennerneve 1 4 Figure TN 3 1 Press Display WINCOWS tee 3 2 AT aa EE A 3 2 PETN Sr 3 3 HA o A e A 3 3 Figure 8 Function Numerical Buttons 3 3 Figure 9 Temp Comp Mode Key and Receptacle ccccooocccncccnoccnnnnonononononnnoconononanonnnononnnnnos 3 5 FEN A RE 3 5 Figure 11 Disconnect Status amp Charging Inductor LEDe 3 6 Figure 12 BOR POSE E 3 6 Figure 13 Banana Plugs to Binding Post scccccsssssccsssssssccccessssccccesessescessescessessessensesssssens 3 7 W NTN 3 8 Figure 15 HI LO Comparator Relay Pins sssscccsssssscesssssssccsccsssscesccsssccscesssssescesssssensesssscess 3 9 Figure 16 9 Pin RS 232 Connector rnnrnnwrannnennuvnnnvnnnnennuvnnnnvnnnvnnevennnennnennenennnennuvnnenennuennusenenene 3 10 Be NEUOo NU U U O IA IA 3 11 Fe 3 12 Pee 3 13 TE E 3 13 FET EE 3 14 FE ER GE E 3 14 Figure 23 Test CUM CNT ET 3 14 Figure 24 Omni Compensator Temperature Sensor 4 3 FAE TE AA O Po O 4 6 SPAT AEE Relay EE EN EE 4 6 Figure 27 Display Function Window
76. ons and messages Before explaining how to make measurements it is useful to describe the sections of the front and rear panel of the 4300C FRONT PANEL The front panel of the 4300C can be broken down into nine parts Figure 3 depicts the regions indicated by their name Range Selection Function Numerical and Keys TC Mode Key and Disconnect Status Test Current Keys Sensor Receptacle LEDs Omni TEMPERATURE COMPENSATOR Disconnect Status HI Hi Tom UNGE 2 V d d LO L d K Bakes Ge EE S E on A Ge fn OAA ee Display Limit Comparator A Source and Sense wem LED Binding Post Figure 3 Front Panel Layout On Off Switch The power switch is a two position ON OFF rocking switch used to apply ON position or disconnect OFF position the AC power source from the internal circuitry of the ohmmeter 3 1 4300C User Manual Display During measurements the display presents 3 windows described in the table below Measurement Window Function Window Figure 4 Display Windows R Range Window The display is also used to prompt the user with alerts and messages Range Selection and Test Current Key Range Selection The 4300C has 3 voltage settings and 6 current ranges The combination of the two result in 16 possible resistance measurement ranges See table 3 Table 3 Voltage Setting Range Selection Table 20mV 200mV 2V a 10A 1 2m0 7 20m0 13 200m0 3 1A 2 20mQ 8 200m0 14
77. owing occurs Remote System System System System Remote System Remote System System System RESET COMMAND gt RANGE 6 lt 2kQ gt Places REM in TX buffer Tiny Display gt Change to R6 gt Places 2k in TX buffer Tiny Display gt Formats Display String 1 6543k gt READING gt Places in TX buffer to VFD D characters gt RANGE 4 gt Change to R4 gt Executes READING query uses Range 4 and last displayed value gt Places in TX buffer next R characters Executes a soft reset of the ADuC834 processor system Syntax Response Example Response RESET Front panel display show soft reset initiation RESETTING is displayed flashing inverse mode for 300ms while all system configurations are returned to power up default RESET lt crlf gt lt crlf gt Notes Resetcpu executes as soft reset of the system by nicely changing the return stack function and popping it Expect a 500ms delay after receiving the linefeed before transmitting next command 4300C User Manual RST COMMAND Sets buffers to power on default Syntax RST lt crlf gt Response lt crlf gt Remote command buffer Serial I O history statistics stability SAVSETUP COMMAND Stores current RAM setup data in NV RAM Syntax SAVSETUP lt crlf gt SAVSETUP QUERY Refreshes the current Setup from NV RAM and then sends it to the remote port Syntax SAVSETUP lt crlf gt Response FF EE DD CC BB AA 99
78. rcuit is maintained across the winding
79. re connections Select the 2V and 1A ranges Adjust RV103 for a reading of 1000 0mQ 0 1 Amp Adjustment Connect the 100 standard resistor to the 4300C using four wire connections Select the 2V and 1A ranges Adjust RV104 for a reading of 10000m0 10mA Adjustment Connect the 1000 standard resistor to the 4300C using four wire connections Select the 2V and 10mA ranges Adjust RV105 for a reading of 100 000 1mA Adjustment Connect the 1kQ standard resistor to the 4300C using four wire connections Select the 2V and 1mA ranges Adjust RV106 for a reading of 1 0000kQ 0 1mA Adjustment Connect the 10kQ standard resistor to the 4300C using four wire connections Select the 2V and 1mA ranges Adjust RV107 for a reading of 10 000kQ 8 4 Chapter 8 Routine Maintenance TCM Calibration REMOVE SENSUR PRESS ENTER OF CLEAR SAHLE CAL LU UE PRESS ENTER UR LEUK LOMNMELT THE SENSOR HHO FRESS ENTER IHFUT AMBIENT TEMP Ge SHUE CHL VALUES FRESS EHTER OF CLEAR XI XII XIII XIV Remove the top cover of instrument Verify that the Omni Compensator Temp Sensor is not connected to the ohmmeter Press ENTER to continue The instrument will perform the TCM Zero Cal The screen will display the following information When prompted by the display apply 1V to TP1 and TP2 follow polarity Press ENTER to continue or CLEAR to return to the zero cal screen While calibr
80. rence from other devices This effect may be reduced by using fully shielded cables such as Valhalla Option K It may also be helpful and will cause the settling time to be reduced if the unused windings of the transformer can be short circuited during the measurement This will significantly reduce the inductance of the winding under test and will also prevent the unused windings from producing dangerous voltages during charging and discharging of the transformer When using the 20mV voltage range the measurement may be subject to the effects of thermal EMF s This effect is seen as noise on the display The best way to reduce this effect is to use a low thermal lead set such as Valhalla Option SL 48 Chapter 9 Special Procedures DISCONNECTING THE CABLES When disconnecting the test leads from the load or from the 4300C extreme care must be taken to ensure that the inductor has been discharged to prevent an extremely high energy high voltage kick back which can be LETHAL to the user and can certainly damage the 4300C There are two methods of discharging the energy in the inductor listed below a Using the Flyback Diode in the 4300C As discussed in Chapter 7 the 4300C has an internal diode which can sink the excess current being discharged from the inductor Therefore turning off the test current and or reducing the 4300C s current range from the original test current to a low value less than 10mA will automatically di
81. return to the previous screen STORING HEN SETUP DATA IN HOVRAM e The screen will display a brief message and the instrument will return to the standard measurement mode TCC Temperature Compensator Calibration This procedure is used to match a 4300C with its Omni Compensator e Verify that the instrument is in a temperature controlled area e Press FUNC TCM 2 to initiate the process CONNECT THE SENSOR e Connect the Omni Compensator to the TCM receptacle on AND PRESS ENTER the front panel of the Ohmmeter e Allow the Omni Compensator to reach ambient temperature Wait 5 to 10 minute before proceeding e Press ENTER to continue INPUT AMBIENT TEMP e Using the numeric keys input a value for the ambient SC temperature Use Clear as a backspace to correct errors e Press ENTER to confirm the value SHUE CAL VALUES e Press ENTER to confirm the value or CLEAR to return to PRESS ENTER OF CLEAR the previous screen e Once the calibration values are stored press TCM and verify that the temperature displayed matches the ambient temperature If the values do not match repeat the procedure 4300C User Manual HLC Hi Lo COMPARATOR MODE Figure 25 HLC LEDs Another useful feature of the 4300C is the Dual Limit Comparator HLC This feature lt gt gt XLO GO H helps eliminate operator DIGITAL LimiT COMPARATOR interpretation of ohmmeter
82. ry UAY W I A A Leading Technology in Precision h 2 y Electronic Measurement amp A Calibration Instrumentation SGJENITIFRIC Model 4300C Programmable Digital u Ohmmeter User amp Maintenance Manual SS 18MiramarMallSanDiego Califo rnia9z2121 Pk es e gt SL A bk 7 5 ZG LE aw vc Se RB IL amp F O12 F www valhallascientific comilvalhalla valhallascientific com Way nese A S SCIEN TIFIC 4300C Programmable u Ohmmeter User amp Maintenance Manual Edition 1 Copyright 2009 Valhalla Scientific Inc All rights reserved Certification Valhalla Scientific Inc certifies that this instrument was thoroughly tested inspected and found to meet published specifications when shipped from the factory Valhalla Scientific Inc further certifies that its calibration measurements are traceable to the National Institute of Standards and Technology to the extent allowed by N I S T s calibration facility Due to continuing product refinement and due to possible parts manufacturer change Valhalla Scientific Inc reserves the rights to change any or all specifications without notice Warranty Statement The warranty period for this instrument is stated on your invoice and packing list Please refer to these to determine appropriate warranty dates Valhalla Scientific Inc will repair the instrument during the warranty period provided it is return to our repair and calibration facility freigh
83. s The brackets are easily installed on the front end of each side rail see Figure 2 The kit is listed in chapter 5 as Option RX 3 Figure 2 Rack Mount Kit Side Rail 8 32 x 1 27 Flot Heod Screws The size of the ohmmeter and the location of its center of gravity dictate that it must be supported on both sides along its entire length through the use of trays or slides If it is to be transported while mounted in a rack it should be supported so as to prevent upward or downward movement It is recommended that blank panels at least 1 75 inches high be installed between this and any other units in the rack to ensure freedom of air flow Under no circumstances should the ambient air temperature around the unit exceed 50 C while the unit is in operation or 70 C when power is removed 1 4 Chapter 1 Inspection Installation SAFETY PRECAUTIONS The power plug must be a three contact device and should be inserted only into a three contact mating socket where the third contact provides a ground connection If power is provided through an extension cable the ground connection must be continuous Any discontinuity in the ground lead may render the unit unsafe for use The Model 4300C utilizes forced air cooling of the internal components This operates continuously and care must be taken to ensure that the intake and exhaust ports remain clear Blocked vents may cause a dangerous overheating condition 430
84. scharge the inductor into the Flyback diode The cables should not be disconnected until the SAFE cable disconnect status LED is illuminated The time required to discharge the inductor into the Flyback diode is given by the formula T LxI V T Discharge time in seconds L Inductance in Henries Current range in Amps V Flyback Diode voltage drop typically 6V For example a 1000 Henry inductor will take approximately 30 minutes to discharge During discharge the 4300C display will read overload until the inductor has completely discharged The reading will then return close to zero 4300C User Manual b Using a Shorting Switch When using a shorting switch instead of the 4300C flyback diode the current stored in the inductor discharges through the cables and switch The current discharges with a time constant calculated from the formula below which is dependent on the test current that was used to charge the inductor Test Current Discharge Time Range Used in Seconds 10 Amps 7xL R 1Amp5xL R 1Amp2xL R lt 1 Amp Not required Where L Inductance in Henries R Total resistance of cables switch and inductor in ohms In a typical application R might be approximately 1 milliohm 0010 and L might be 1000 Henries If the 10 amp range of the 4300C was used to measure the inductor 7 000 000 seconds are required 11 weeks to discharge it The 4300C may be disconnected at any time provided the short ci
85. scribed as follows DAV NRFD NDAC May be asserted by any talker indicates that a valid data byte is present on the data wires May be asserted by any listener Indicates that the listener is not ready to receive data May be asserted by any listener Indicates that the listener has not yet finished reading the data byte The transfer of data on the bus is controlled by these three handshake wires It is important to note that the drivers for the handshake wires are all connected for wired on operation That is as long as any of the devices on the bus asserts a handshake line it will remain true There must be a complete consensus among the devices for any handshake wire to be high false The talker first waits for all devices to be ready to accept data checks that NRFD is false then puts one byte of data on the bus and asserts DAV It waits for all devices to indicate that the data has been accepted Chapter 6 Remote Operations IEEE Interface that is NDAC to become false before starting to transfer the next byte of data This handshake protocol assures that data on the bus is transferred at the speed of the slowest device on the bus Data is sent in 8 bit bytes on the DIO wires usually as in the 4300C using the ISO 7 standard ASCII characters Table 12 lists each ASCII character and the bus messages applicable to each 0 1 2 3 4 5 6 7 COLUMN ISO BIT amp 7 0 0 0 1 1 1 1 ROW DIO LINE 6
86. t device with a 9 pin D type shell RS232 connector located on the rear panel Table 14 shows the 9 pin connector Female with its pin number assignments When the 4300C is set up with a RS232 interface please check the following points e Many devices require a constant high signal on one or more input pins e Ensure that the signal ground of the equipment is connected to the signal ground of the external device e Ensure that the chassis ground of the equipment is connected to the chassis ground of the external device e Do not use more than 15 meters of cable to connect devices to a PC e Ensure the same baud rate is used on the device as the one used on PC terminal e Ensure the connector for both sides of cable and the internal connection lines meet the demands of the instrument NR 4300C User Manual Table 14 RS 232 Connector Pin Configuration Pin Pin Function Not Connected Receive Data RxD input Transmit Data TxD output Not Connected Signal Ground GND Not Connected Not Connected Not Connected Not Connected kA LD CON DU BW Fb Connecting to a Computer A personal computer with a COM port is essential in order to operate the 4300C via RS232 interface The connections between 4300C and computer are as follows L Connect one end of a RS232 cable to the computer ll Connect the other end of the cable to the RS232 port on the 4300C LL Turn on the 4300C IV Tur
87. t prepaid No other warranty is expressed or implied Valhalla Scientific Inc is not liable for consequential damages Permission and a Return Material Authorization number RMA must be obtained directly from the factory for warranty repairs No liability will be accepted if returned without such permission Document History All Editions and Updates of this manual and their creation date are listed below The first edition of the manual is 1 The edition number increases by 1 whenever the manual is revised Updates which are issued between editions contain replacement pages to correct or add additional information to the current Edition of the manual Whenever a new Edition is created it will contain all of the update information for the previous Edition Each new Edition or Update also includes a revised copy of this documentation history page Edition 1 cc cc ccc ecececcscscsccccecscuceccececucsaececscucaeaesecsesaesecscucaseecscucsessscucesaeusescusaeaess June 2009 Safety Symbols Instruction manual symbol affixed to product Indicates that the user must refer to the user manual for specific WARNING or CAUTION information to avoid personal injury or damage to the product Warning Risk of Electrical Shock A DANGER Procedure Practice or Condition that could possibly cause damage to Equipment or permanent loss of data Procedure Practice or Condition that could possibly cause bodily injury or deat
88. te that does not accept that key will have no effect to change the state In addition if the KEY X commands are sent without enough interval the key handler task will not have executed and the key press can be overwritten by the next key command and the previous one is skipped This is due to no buffering of remote key presses Chapter 6 Remote Operations RS 232 Interface LOCAL COMMAND Returns meter to local mode remote LED off Goto Local Syntax LOCAL Returns lt crlf gt Power on default LOCAL mode Notes REMOTE mode is selected when the meter receives a valid character not lt crlf gt Once selected all keys are disabled and will not be scanned Therefore no key beeps with the exclusion of the LOCAL key at the top right of the key pad This key is active in REMOTE mode and will extinguish the REMOTE LED and transition the device to the front panel local user mode LOG COMMAND Selects LOG mode on or off Syntax LOG lt ON or OFF gt 0 synonymous with OHMS Example LOG ON O lt crlf gt space or comma 13 693 lt crlf gt 13 664 lt crlf gt LOG ON 4 default 13 693 lt crlf gt 13 664 lt crlf gt LOG ON 6 13 693 23 2 0003931 13 699 20 0 Possible options responses as if the following queries sent 0 OHMS 1 OHMS ATOD1 RDNG 2 ATOD1 3 ATOD1 RDNG 4 RDNG 5 RDNG RANGE 6 OHMS EXTEMP Setup TC Load_Coeff COMPENSATED_OHMS Ref_Degress 7 EXTEMP 8 EXTEMP RDNG Run
89. the bus must have its own unique address Operating two devices at the same address will produce undefined results and is not recommended 2 Avoid setting the 4300C to address 0 all switches off or to address 31 all switches on as this may interfere with the system controller 3 If the setting of the switches is changed power must be cycled in order to place the new address into memory Note In all future examples we will assume that the address is set to 12 6 7 4300C User Manual REMOTE AND LOCAL STATES Local State When the 4300C is in the local state the REMOTE indicator on the front panel is extinguished and full manual control as described in Chapters 3 and 4 may be performed The user should also note that the 4300C will ignore commands from the GPIB while in the local state The 4300C automatically powers up in the local state Other methods for placing it in the local state are by cycling power or by sending a return to local RTL command over the bus This is done in HP Basic using the command LOCAL 712 To ensure compatibility with all controllers the 4300C may also be returned to the local state by sending it the code L Remote State In this state the REMOTE indicator on the front panel is illuminated and all controls on the front panel are disabled except the power switch The remote state may only be entered via the bus If the 4300C receives its listen address while the REN line is asserted it wi
90. to listen or talk Only one device may talk at any one time The interconnecting cable consists of sixteen signal wires and eight ground returns linking devices into a complete system 1 Eight data wires DIO 0 thru DIO 7 2 Five management wires ATN EOI SRQ IFC and REN 3 Three handshake wires DAV NRFD and NDAC Each cable connector is a plug socket combination to permit daisy chaining of units It should be noted that these wires use inverse logic That is to say that a low level indicates the true asserted state and a high level indicates a false non asserted state 4300C User Manual DETAILED DESCRIPTIONS OF BUS OPERATIONS The five management wires are described as follows ATN EOI SRQ IFC REN Asserted by the controller whenever an address or a command is present on the bus May be asserted by the controller or any talker With ATN true EOI indicates that the controller is polling devices With ATN false EOI is asserted by the talker to indicate the end of data May be asserted by any device This indicates that the device requires attention e g a fault has occurred Normally the controller will respond by polling to determine which device requires service May be asserted only by the controller This line initializes the bus to a reset state May be asserted only by the controller This signal places the addressed device into the remote mode The three handshake wires are de
91. tures installed This section of the manual refers to the standard model without any optional features or modifications If the 4300C that you are using features terminals or connectors not described in this section please refer to Chapter 10 of this manual for addendums that reference the particularities of your model Here is an outline to the use of each of the rear panel controls and connectors aci J Z Connectors gende Line Power R5 232 Connecto USB Connector Fuse Holder l Option Line Voltage _ Figure 14 4300C Rear Panel switch Line Voltage Switch The line voltage switch allows the user to select the power settings according to the local AC line voltage By sliding the switch upwards the II number 115 will appear on the switch The instrument is now configured for line voltages of 115VAC 10 By sliding the switch downwards the number 230 will appear The instrument can now be used with line v NI voltages of 230VAC 10 Prior to powering on the ohmmeter it is important to verify that the switch is set for the correct line voltage Selecting the incorrect line voltage setting may cause damage to the instrument 3 8 Chapter 3 Getting Started Fuse Holder The line power fuse must match the line voltage selection as follows e 105 125VAC 3A SLO BLO e 210 250VAC 1 5A SLO BLO The fuse holder is located on the rear panel see Figure 1 To install a fuse
92. ups as follows 1 2 3 4 Addressed Command Group applied only to addressed devices Universal Command Group applied to all devices Listen Address Group set of device listen addresses Talk Address Group set of device talk addresses Data in the above command groups is sent with ATN true These type of commands are understood by all devices using the IEEE 488 standard When data is sent with ATN false it is referred to as a device dependent command A device dependent command is specific to a particular device and may or may not be understood by other devices Chapter 6 Remote Operations IEEE Interface SETTING THE IEEE ADDRESS The IEEE address is the method by which the system controller distinguishes one device on the bus from another The address of the 4300C is determined by the setting of a binary weighted switch on the rear of the instrument Here are two examples to help you set the address Example 1 Switches 1 2 and 16 are OFF or 0 and switches 4 and 8 are ON or 1 The resulting address is 1Xx0 2x0 4x1 8x1 16x0 4 8 12 Example 2 Switches 2 and 4 are OFF or 0 and switches 1 8 and 16 are ON or 1 The resulting address is 1x1 4 2x0 4x0 8x1 16x 1 1 8 16 25 The address you choose is entirely dependent on your application and by the type and quantity of devices on your IEEE bus Some guidelines to follow are 1 Each device on
93. within the microcontroller According to the data received from the keypad a signal is sent to activate the appropriate relay on the current source circuitry RS 232 The RS 232 data is also sent and received by the micro controller Display This is the visual interface to the user The display receives its data directly from the micro controller Keypad Board 4300C 701 This section of the ohmmeter contains the keypad and the LED indicators for the TCM and HLC function Keypad The keypad is used to send commands to the micro controller HLC LEDs These LEDs indicate the result of the HLC comparison TCM LEDs These LEDs indicate the status of the temperature compensation mode Chapter 7 Theory of Operations DETAILED CIRCUIT DESCRIPTIONS This section describes in detail the operation of the main circuits of the Model 4300C The reference designators used in this section refer to the drawings included at the back of this manual Current Source The operation of the Current Source is described in the following paragraphs All components in this section can be found on Schematic 4300C 070 Figure 40 Current Safe Source Block Diagram to p Controller Power SCHERER Protection Charging to u Controller lt Comparator tangas Error Output Amplifier Stage ON OFF I from u Controller Range Select Range from p Controller Switching Reference I

Model 4300C - Valhalla Scientific, Inc

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