Operator's Manual Model SM2040 6½ Digit Digital Multimeter Model SM2042 6½ Digit Multi-Function Digital Multimeter Model SM2044 6½ Digit LCR Sourcing Digital Multimeter Signametrics Corporation February 2003
CAUTION In no event shall Signametrics or its Representatives are liable for any consequential damages whatsoever (including, without limitation, damages for loss of business profits, business interruption, loss of business information, or other loss) arising out of the use of or inability to use Signametric's products, even if Signametrics has been advised of the possibility of such damages.
TABLE OF CONTENTS 1.0 INTRODUCTION .................................................................................................................................................7 1.1 SAFETY CONSIDERATIONS ..........................................................................................................................7 1.2 MINIMUM REQUIREMENTS .........................................................................................................................8 1.3 FEATURE SET ...............
.2 CURRENT MEASUREMENTS ......................................................................................................................25 4.2.1 Improving Current Measurements .........................................................................................26 4.2.2 Low Level DC Current Measurements...................................................................................26 4.2.3 Extended DC Current Measurements (SM2044) ................................................................
DMMDelay .....................................................................................................................................57 DMMDisableTrimDAC...................................................................................................................57 DMMDisArmTrigger ......................................................................................................................58 DMMDutyCycleStr ..............................................................................
DMMSetACCapsLevel ....................................................................................................................92 DMMSetACVSource .......................................................................................................................93 DMMSetAutoRange ........................................................................................................................94 DMMSetBuffTrigRead ...............................................................................
1.0 Introduction Congratulations! You have purchased a Personal Computer (PC) Plug-in instrument with analog and systems performance that rivals the best, all-in-one box, instruments. The SM2040 series digital multimeters (DMMs) are easy to setup and use, have sophisticated analog and digital circuitry to provide very repeatable measurements, and are protected to handle any unexpected situations your measurement environment may encounter.
1.2 Minimum Requirements The SM2040 series of system DMMs are precision plug-in modules that are compatible with IBM type personal computers (PCs), from the 486 to the Pentiums. They require a half-length expansion slot on the PCI bus. A mouse must be installed when controlling the DMM from the Windows Control Panel. The SM2040 comes with a Windows' DLL, for operation with Windows' Version 95/98/Me/2000/XP and NT4.0. 1.
2.0 Specifications The following specifications are based on both, verification of large number of units as well as mathematical evaluation. They should be considered under the environment specified. 2.1 DC Voltage Measurement Input Characteristics • Input Resistance 330 mV & 3.3 V Ranges: >10 GΩ • Input Resistance 33 V & 330 V Ranges: 10 MΩ Accuracy ± (% of reading + Volts) [1] Range 330 mV 3.3 V 33 V 330 V Full Scale 6 ½ Digits 330.0000 mV 3.300000 V 33.00000 V 330.
Accuracy ± (% of reading + Volts) [1] Range Frequency 330 mV 10 Hz - 20 Hz 20 Hz - 47 Hz 47 Hz - 10 kHz 10 kHz - 50 kHz 50 kHz - 100 kHz 10 Hz - 20 Hz 20 Hz - 47 Hz 47 Hz - 10 kHz 10 kHz - 50 kHz 50 kHz - 100 kHz 10 Hz - 20 Hz 20 Hz - 47 Hz 47 Hz - 10 kHz 10 kHz - 50 kHz 50 kHz - 100 kHz 10 Hz - 20 Hz 20 Hz - 47 Hz 47 Hz - 10 kHz 10 kHz - 50 kHz 50 kHz - 100 kHz 3.3 V 33 V 250 V 24 hours 23°C ± 1°C 3.0 + 350 µV 0.92 + 150 µV 0.13 + 100 µV 0.55 + 160 µV 5.3 + 350 µV 3.0 + 2 mV 0.93 + 1.3 mV 0.
ACV Range 330 mV 3.3 V 33 V 250 V Lowest specified input voltage (Vp-p) 0.08 V 0.80 V 8V 80 V Full Scale reading ±0.95 V ±9.5 V ±95.0 V ±350.0 V Resolution Typical Accuracy 23°C ± 5°C One Year [1] 1 mV 10 mV 100 mV 1V 2.0% ±17 mV 3% ±160 mV 3% ±1.4 V 3% ±12 V [1] Median measurements require a repetitive signal with frequency range of 30 Hz to 30 KHz. 2.
2.5 Resistance Measurements 2.5.1 2-wire and 4-wire Accuracy ± (% of reading + Ω) [1] Range [2] 33 Ω [3] 330 Ω 3.3 kΩ 33 kΩ 330 kΩ 3.3 MΩ 33 MΩ 330 MΩ [3] Full Scale 6 ½ Digits 33.00000 Ω 330.0000 Ω 3.300000 kΩ 33.00000 kΩ 330.0000 kΩ 3.300000 MΩ 33.0000 MΩ 330.00 MΩ Resolution 10 µΩ 100 µΩ 1 mΩ 10 mΩ 100 mΩ 1Ω 100 Ω 10 kΩ Source current 10 mA 1 mA 1 mA 100 µA 10 µA 1 µA 100 nA 10 nA 24 hours 23°C ± 1°C 0.0038 + 1 mΩ 0.0037 + 4.5 mΩ 0.0023 + 28 mΩ 0.0025 + 300 mΩ 0.0055 + 3.2 Ω 0.036 + 70 Ω 0.
2.8 Additional Component Measurement 2.8.1 Diode Characterization • Available DC current values 100 ηA, 1 µA, 10 µA, 100 µA and 1 mA. SM2044: 10 mA constant current plus variable current from 10 ηA to 12.5 mA • Typical Current Value Uncertainty 1% • Typical Voltage Value Uncertainty 0.02% • Maximum diode voltage compliance 4 V 2.8.2 Capacitance Measurement (SM2042, SM2044) Accuracy ± (% of reading + Farads) [1] Range 10 ηF 100 ηF 1 µF 10 µF 100 µF 1 mF 10 mF Full Scale 4 ½ Digits 11.999 ηF 119.
2.9 Timing Measurements (SM2042, SM2044) 2.9.1 Threshold DAC • The Threshold DAC is used for selecting a detection threshold to give optimal frequency and timing measurements. ± (% of setting + volts) Selected VAC range [1] Threshold range (DC level) 330 mV 3.3 V 33 V 250 V -1.0 V to +1.0 V -10.0 V to +10.0 V -100.0 V to 100.0 V -500 V to 500 V Threshold DAC resolution 0.5 mV 5.0 mV 50 mV 500 V Highest allowed input Vp-p Typical one year setting uncertainty 1.900 V 19.00 V 190.0 V 850.0 V 0.
2.9.4 Pulse Width ± (% of reading + sec) Polarity Frequency range Resolution Width range Positive or negative pulse widths 1 Hz to 100 kHz 2 µs 2 µs to 1 s Typical Uncertainty 0.01 +/- 4 µs 2.9.5 Totalizer • Active edge polarity: Positive or negative transition • Maximum count: 10^9 • Allowed rate: 1 to 30,000 events per second • Uses Threshold DAC 2.10 Trigger Functions 2.10.
Parameter Typical source resistance Frequency range / resolution Frequency stability Closed Loop [1] Open Loop 250 Ω 2 Hz to 75 kHz / 2 Hz 100 ppm ± 1 Hz [1] 5 rps or lower measurement rate is required for the closed loop mode. 2.11.3 DC Current Source Compliance Voltage Resolution [1] Minimum level Accuracy 23°C ± 10°C One Year 1.25 µA 4.2 V 500 pA 1 ηA 1% + 10 ηA 12.5 µA 4.2 V 5 ηA 10 ηA 1% + 100 ηA 125 µA 4.2 V 50 ηA 100 ηA 1% + 500 ηA 1.25 mA 4.2 V 500 ηA 1 µA 1% + 5 µA 12.
2.12 Accuracy Notes Important: All accuracy specifications for DCV, Resistance, DCI, ACV, and ACI apply for the time periods shown in the respective specification tables. To meet these specifications, the System Calibration function must be performed once a day. System Calibration is a simple software operation that takes a few seconds. Do it by executing the DMMCalibrate() command, or selecting S-Cal in the control panel.
2.13 Other Specifications Temperature Coefficient, All Functions Less than 0.1 x accuracy specification per °C at 23C ± 5°C Reading Rate (user selectable) • 0.5 to 1,000 readings per second (rps) • Up to 10 rps, 6 ½ digits • Up to 30 rps, 5 ½ digits Hardware Interface PCI Bus Overload Protection (voltage inputs) 300 VDC, 250 VAC Isolation 300 VDC, 250 VAC from Earth Ground Maximum Input (Volt x Hertz) 8x106 Volt x Hz normal mode input (across Voltage HI & LO).
3.0 Getting Started After unpacking the DMM, please inspect for any shipping damage that may have occurred, and report any claims to your transportation carrier. The DMM is shipped with the Digital Multimeter module; four floppy disks which contain the various software panels and drivers plus the calibration data specific for the unit, and this Operator's manual. 3.
3.4 DMM Input Connectors Before using the DMM, please take a few moments and review this section to understand where the voltage, current, or resistance and other inputs and outputs should be applied. This section contains important information concerning voltage and current limits. Do not exceed these limits, as personal injury or damage to the instrument, your computer or application may result. Figure 3-1. The DMM input connectors.
TRIG / GUARD Both the Trigger and Guard functions are at the DIN-7 connector. This group of pins includes the positive and negative hardware trigger input lines and the two SM2044 Guarded Measurement Force and Sense signals. The external trigger initiates reading(s) into the onboard buffer, and the 6W guard signals facilitate incircuit resistor measurements by means of isolating a loading node. The DIN-7 plug can be ordered from Signametrics and is also available at many electronic hardware distributors.
3.6 Using the Control Panel Figure 3-2. The Control Panel for the SM2044. The three main groups include Measure, Source and Range buttons. The 8 Range buttons are context sensitive such that only “330m, 3.3, 33 and 250 appear when in AC Voltage Functions, “3.3m 33m 330m 2.5” appear when in Current Functions, etc. Note: All of the controls described below correspond to their respective software function, which can be invoked within your control software or as objects in a visual programming environment.
application due to the uncertainty of the DMM range, as well as the extra time for range changes. Locking a range is highly recommended when operating in an automated test system, especially to speed up measurements. Another reason to lock a range is to control the input impedance in DCV. The 330 mV and 3.3 V ranges have virtually infinite input impedance, while the 33 V and 330 V ranges have 10 MΩ input impedance.
4.0 DMM Operation and Measurement Tutorial Most of the SM2040 measurement functions are accessible from the Windows Control Panel (Figure above). All of the functions are included in the Windows DLL driver library. To gain familiarity with the SM2040 series DMMs, run the Windows ‘SETUP.EXE’ to install the software, then run the DMM, as described in the previous section. This section describes in detail the DMM’s operation and measurement practices for best performance. 4.
Figure 4-1. Make Voltage ACV measurements with the source ground attached to the SM2040 V,Ω - to minimize “Common Mode” measurement problems. 4.1.3 AC Peak-to-Peak and Crest Factor (SM2042, SM2044) Measurement of Peak-to-Peak, Crest Factor and AC Median values requires a repetitive waveform between 30 Hz and 100 kHz. The DMM must be in AC voltage measurement mode, with the appropriate range selected. Knowing the Peak-to-Peak value of the waveform is useful for setting the Threshold DAC (described below).
Figure 4-2. AC and DC Current measurement connection. 4.2.1 Improving Current Measurements When making sensitive DC current measurements, be sure to use the Relative function to zero out any residual errors of the SM2040. Disconnecting all terminals to the DMM and performing Relative in the appropriate DCI range easily accomplish this. Using the S-Cal (DMMCalibrate()) prior to activating Relative will improve accuracy further. Although the SM2040 family is designed to withstand up-to 2.
4.3 Resistance and Leakage Measurements Resistance is measured using eight (six in the SM2040) precision current sources, with the DMM displaying the resistance value. Most measurements can be made in the 2-wire mode. The 4-wire ohms is used to make low value resistance measurements. All resistance measurement modes are susceptible to Thermo-Voltaic (Thermal EMF) errors. See section 4.3.5 for details. 4.3.1 2-Wire Ohm Measurements The DMM measure using 330Ω to 33 MΩ ranges.
Figure 4-3. The I- and I+ sense leads should be closest to the body of the resistor when making 4WΩ measurements. 4.3.3 Using Offset Ohms function Inadvertent parasitic leakage currents, Thermo voltaic voltages and other voltages in series can effect resistance measurements with the measured resistance. This is common particularly when doing in-circuit measurements, and it could manifest as having a significantly different readings when changing Ohms ranges.
Figure 4-4. 6-wire guarded in-circuit ohms measurement configuration. The current compliance of the Guard Force is limited to a maximum of 20 mA and is short circuit protected. The resistor connected between the low of the 4-wire terminals and the guard point is the burden resistor, or Rb. Due to the limited guard source current, this resistor can not be lower than Rbmin: Rbmin = Io * Rx / 0.02, where Io is the ohms source current for the selected range, and Rx is the resistance being measured.
Figure 4-5. Leakage Test Configuration. Measurement of reverse diode leakage at 5V. 4.3.6 Extended Resistance Measurements (SM2044) The Extended Resistance measurement function operates as complement of the standard resistance measurement. Where the last forces a predefined current, this function forces specified voltage. Where the normal resistance measurement is limited to pre defined current sources, this function has a variable voltage, and it limits current flow by an external sense resistor.
Figure 4-6. Extended Ohms range. 4.3.7 Effects of Thermo-Voltaic Offset Resistance measurements are sensitive to Thermo-Voltaic (Thermal EMF) errors, which can be caused by poor test leads, relay contacts and other elements in the measurement path. These errors affect all measurement methods, including 2-Wire, 4-Wire, 6-Wire and 3-Wire (guarded 2-Wire ohms). To quantify this error, consider a system in which signals are routed to the DMM via a relay multiplexing system.
measurement it is important to use good quality shielded cables with a low leakage dielectric. Even with a good dielectric, if a significant length is involved, an error would result due to leakage. Figure 4.7 exemplifies this error source. It is important to emphasize that in addition to the finite leakage associated with the distributed resistance, RL, there must also be a voltage present between the two conductors, the shield and the center lead, for leakage current to develop.
the accuracy and stability of the DMM. It also allows monitoring of the PC internal temperature, which is important for checking other instruments in a PC-based test system. 4.6 Diode Characterization The Diode measurement function is used for characterizing semiconductor part types. This function is designed to display a semiconductor device’s forward or reverse voltage. The DMM measures diode voltage at a selected current.
ability of this function to measure capacitors that have a very low value parallel resistance, which is impossible to do using conventional methods. This test function operates by figuring the complex impedance and extracting from it both, the capacitance and resistance. The measurement is practical down to a few hundred Pico Farads, and up to several thousands micro Farads, with parallel resistances as low as 20Ω to 300Ω depending on range.
4.11.2 Analog Threshold Trigger This mode triggers the DMM at a specific input level. A command to the DMM sets a threshold value and arms the DMM Analog trigger. The DMM’s local controller waits for the level crossing and captures up to 64 readings, which are saved on board at the current DMM measurement function, range and rate. The reading rate must be set to 10 rps or higher. You can abort this mode by sending the DMM a Disarm command to the Analog Trigger. 4.11.
Figure 4-10. AC coupled timing measurements with Threshold DAC. In Figure 4-10, the DMM is set to 3.3 ACV range, while the input is a 10% duty-cycle wave with 5 V peak-topeak. Due to AC coupling, the input at the comparator is –0.5 V to + 4.5 V. The Median Value is +2.0 V, which would be the optimal Threshold value. Figure 4-11. Comparator and Threshold DAC Settings 4.12.2 Frequency and Period Measurements Both Freq. and Per check boxes are only visible when ACV or ACI functions are selected.
4.12.3 Duty Cycle Measurement Duty Cycle of signals from 1 Hz to 100 kHz can be measured. The minimum positive or negative pulse width of the signal must be at least greater than 2 µs. When measuring duty cycle precisely, the voltage at which the measurement is made is important, due to finite slew rates of the signal. With the SM2042 and SM2044, the Threshold voltage can be set for precise control of the level at which duty cycle is measured.
All three source functions use the V,Ω+, and the V,Ω- terminals of the SM2044. 4.13.1 DC Voltage Source The SM2044 has a fully isolated bipolar DC voltage source. Two modes of operation are available: fast settling or closed loop. In the ClosedLoop mode the DMM monitors the voltage source output, and updates it using the composite 16 bit DAC, at a rate proportional to the set measurement rate. The ClosedLoop mode offers the best accuracy and resolution.
Figure 4-14. Generating AC voltage. Monitoring of the output in closed loop operation. 4.13.3 DC Current Source The SM2044 has a fully isolated uni-polar DC current source with five ranges. It uses the 12-bit DAC to control current level. This source function is useful for parametric component measurements as well as for system verification and calibration, where a precise DC current is necessary to calibrate current sensing components. For improved resolution of the current source, use the Trim DAC.
Figure 4-15. Sourcing DC current and measuring voltage in the two-wire configuration. This function can be used for semiconductor parametric tests. 4.14 Synthesizing Resistance (SM2044) The SM2044 synthesizes resistance using an iterative method, which requires repeated reading of the DMM to make corrections to the synthesized value. While in synthesizing resistance, the readings return the measured value.
Selecting the appropriate external resistor is very important. It sets the accuracy and range of the synthesized value. Functions associated with the synthesis of resistance include DMMSetExternalShunt(), which sets the value of the external shunt, and DMMSetResistance(), which control the value to be synthesized. The external resistor should be 100Ω to 10MΩ. Set the measurement to 10 or higher. 20rps is optimal. The Closed loop flag does not have an effect on this function.
4.15.2 Multiplexing with the SM2040 DMMs For two wire measurements, the SM2040 DMM must be connected to the A-Bus or the scanner, or to both, the ABus and C-Bus for 4-Wire measurements (assuming an SM4040 or SM4042 scanner). It is important to consider system-settling time when making measurements. Time delays exist in any measurement system. These delays are contributed by various sources. These include the scanner’s relay actuation times, the DMM input settling and wiring capacitance.
There are several SM2040 family commands to considered for this operation: DMMSetTrigRead(), DMMSetBuffTrigRead(), DMMReadMeasurement(), DMMReady(), DMMReadBuffer() and DMMReadBufferStr(). Referring to figure 4.17, the total time it takes the DMM make a reading must be set to be shorter than t-Delay, for completion of the measurements prior to the selection of the next channel. 4.16 Measuring Temperature With Thermocouples Version 1.
5.0 Windows Interface The Windows interface package provided with the SM2040 series DMM is a 32bit DLL based modules, which includes both, a DLL and a windows Kernel driver. This package is sufficient for most windows based software being used to control the DMM. 5.1 Distribution Files The distribution diskette contains all the necessary components to install and run the DMM on computers running any of the Microsoft® Windows™ operating systems.
File Description SM2044.exe Visual Basic DMM control panel executable Msvcrt.dll System file. Installs in your C:\WINDOWS\SYSTEM directory. Windrvr.vxd Win98/95/Me Virtual Device Driver. Installs by ‘setup’ in your C:\WINDOWS\SYSTEM\VMM32 directory. Windrvr.sys Win NT Virtual Device Driver. Installs by ‘setup’ in your C:\WINNT\SYSTEM32\DRIVERS directory. Install.doc Installation instructions in MS Word Important Note about the SM40CAL.DAT file: The file SM40CAL.
During initialization (DMMInit()), the driver reads various parameters such as DMM type (SM2040/42/44), and serial number, and then reads the corresponding calibration information from the SM40CAL.DAT file. The DMMInit() function reads the information from these files to initialize the DMM. DMMInit accepts parameters that are the names of these files. A qualified technician may modify individual entries in the calibration file, then reload them using the DMMLoadCalFile command. 5.
* Exmp2040.C Exmp2040.EXE * * A simple Windows .EXE example for demonstrating the SM2040,42,44 * DMMs using "C" * Sets Function to VDC, Range to 33V, rate to 10rps. * Display five measurements using a Message box. *********************************************************************** * Make sure SM204032.lib is included in the libraries. For Microsoft * Version 4.0 C++ and above, place under 'Source Files' in the * Workspace, along side with Exmp2040.
5.3 Visual Basic Front Panel Application The Visual Basic front panel application, SM2044.EXE, is an interactive control panel for the SM2040 DMM. When it loads it will take a few seconds to initialize and self calibrate the hardware before the front panel is displayed. The push buttons labeled V, I, etc. control the DMM function. As you push a function, the front panel application will switch the DMM to the selected range and function. Autorange mode is selected by pushing the AutoRange check box.
i = DMMInit(nDmm,"C:\sm40cal.dat") 'Initialize and load cal file i = DMMSetFunction(nDmm, VDCFunc) 'Set DMM to DCV function i = DMMSetRange(nDmm, Range2) 'Select the 33V range i = DMMSetRate(nDmm, RATE_10) 'Set measurement rate to 10 rps End Sub Private Sub ReadBotton_Click() Dim i As Long Dim dReading As Double i = DMMRead(nDmm, dReading) TextReading.Text = dReading End Sub 'Read Botton Click action. 'Any time this botton is pressed 'the DMM takes a reading and displays it.
5.4 Windows DLL Default Modes and Parameters After initialization, the Windows DLL default modes and parameters on your DMM are set up as follows: • • • • • • • • • Autoranging: Off Function: DC Volts Range: 330V Relative: Off Synchronized Mode: Off Measurement rate: 10 rps Temperature units are set to °C Offset Ohms: Off AC Caps level: 0.45V Peak. 5.5 Using the SM2040 DLL with LabWindows/CVI® When using the SM2040 DLL with LabWindows/CVI, you should read the LabWin.
5.6 Windows Command Language The following section contains detailed descriptions of each function of the Windows command language. Those commands that pertain to only the SM2040 are indicated. Most functions return an error code. The code can either be retrieved as a string using DMMErrString function, or looked up in the SM204032.H header file. The UserDMM.H file contains all the pertinent definitions for the DMM ranges functions etc.
DMM_OKAY Operation successfully terminated Negative value Error code. Example double Buffer[64]; DMMArmAnalogTrigger(0,64,1.5); while( ! DMMReady(0)); for(i=0; i < 64 ; i++) j = DMMReadBuffer(0, &Buffer[i]); DMMArmTrigger SM2040 ; SM2042 ; SM2044 ; Description Arm DMM for external trigger operation. #include "sm204032.h" int DMMArmTrigger(int nDmm, int iSamples) Remarks Setup the SM2040 for external hardware trigger operation. Following reception of this command the DMM enters a wait state.
Return Value The return value is one of the following constants. Value Meaning DMM_OKAY Operation successfully terminated Negative Value Error code. Example double Buffer[64]; DMMArmTrigger(0,64); while( ! DMMReady(0)); for(i=0; i < 64 ; i++) j = DMMReadBuffer(0, &Buffer[i]); DMMBurstBuffRead SM2040 ; SM2042 ; SM2044 ; Description Setup the DMM for Triggered operation. #include "sm204032.h" #include "UserDMM.
Example double Buffer[50]; DMMBurstBuffRead(0, 4, 50); // 4 setteling readings for each // measurement, and take 50 readings while( ! DMMReady(0) ); // wait for completion for(i=0; i < 50 ; i++) // read 64 readings from DMM’s // on-board buffer j = DMMReadBuffer(0, &Buffer[i]); DMMBurstRead SM2040 ; SM2042 ; SM2044 ; Description Setup the DMM for mutiple readings operation, sending back measurements as they come. #include "sm204032.h" #include "UserDMM.
Example double Reading[250]; DMMBurstRead(0, 10, 250); // settle 10 reads., 250 samples for(i=0; i < 250 ; i++) // read 250 meas. as they come while( ! DMMReadMeasurement(0 , Reading[i]) ); DMMCalibrate SM2040 ; SM2042 ; SM2044 ; Description Internally calibrate the DMM. #include "sm204032.h" int DMMCalibrate(int nDmm) Remarks This function re-calibrates the DMM, and returns it to the current operating mode. Parameter Type/Description nDmm int Identifies the DMM.
Return Value Integer error code.. Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code Example int status = DMMCleanRelay(0, 2, 100); // Shake K2 1000 DMMClearMinMax SM2040 ; SM2042 ; SM2044 ; Description Clears the Min/Max storage. #include "sm204032.h" int DMMClearMinMax(int nDmm) Remarks This function clears the Min/Max values, and initiates a new Min/Max accumulation. See DMMGetMin for more details. Parameter Type/Description nDmm int Identifies the DMM.
Negative Value Example Error code int status = DMMClosePCI(0); DMMDelay SM2040 ; SM2042 ; SM2044 ; Description Wait for a given time. #include "sm204032.h" int DMMDelay(double dTime) Remarks Delay of dTime seconds. dTime must be a positive double number between 0.0 and 100.0 seconds. Parameter Type/Description dTime double Delay time in seconds. Return Value The return value is one of the following constants.
Negative Value Example Error code DMMDisableTrimDAC(0); // Remove Trim DAC from operation DMMDisArmTrigger SM2040 ; SM2042 ; SM2044 ; Description Abort trigger operation. int DMMDisArmTrigger(int nDmm) Remarks Return Value This function sends the DMM a trigger termination command. If the DMM is waiting for a trigger, it will exit the wait mode, and be ready for a new operation.
Negative Value Example Error code char cBuf[64]; int status = DMMDutyCycleStr(0, cBuf); DMMErrString SM2040 ; SM2042 ; SM2044 ; Description Return the string describing the error code. #include "sm204032.h" int DMMErrString(int iErrorCode, LPSTR lpszError, int iBuffLength) Remarks This function returns a string containing the error description which corresponds to the iErrorCode. The error string is placed at lpszError. Parameter Type/Description iErrorCode int Error code.
Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpszReading LPSTR Points to a buffer (at least 64 characters long) to hold the converted result. Return Value The return value is one of the following constants. Value Meaning DMM_OKAY Operation successfully completed. DMM_CNT_RNG Frequency counter is over or under range.
DMMGetBusInfo SM2040 ; SM2042 ; SM2044 ; Description Returns the PCI Bus and Slot numbers for the selected DMM. int DMMGetBusInfo(int nDmm, int *bus, int *slot) Remarks This function reads the PCI bus and slot numbers for the selected DMM. . It provides means to relate the physical card location to the nDmm value by detecting the location of a DMM in the PCI system tree. This function actually scans the hardware rather then look up the information in the registry.
Value Meaning any positive number Length of the date string Negative number Error code Example char cBuf[64]; int status; status = DMMGetCalDate(0, cBuf); DMMGetdB SM2040 ; SM2042 ; SM2044 ; Description Get dB deviation from the reading at the time relative was activated. #include "sm204032.h" int DMMGetdB(int nDmm, double *lpdDev) Remarks This function returns a double floating value that is the dB deviation relative to the reading made just before the relative function was activated.
nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpszDB LPCSTR Points to a buffer (at least 64 characters long) to hold the result. The return value will consist of a leading sign a floating-point, and a ‘dB’ units specifier Return Value Integer string length if successful, or an error code..
nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpdDev double * Pointer where the deviation value is to be saved. Return Value Integer error code.. Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code Example double error; int status = DMMGetDeviation(0, &error); DMMGetDeviatStr SM2040 ; SM2042 ; SM2044 ; Description Get percent deviation from the reading at the time relative was activated. #include "sm204032.
Remarks This function returns the combined DMM function/range code. See UserDMM.h for the complete set of codes. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Return Value Integer value corresponding to the currently set DMM function/range, or an error code. The following are a few examples of the returned value. Value Meaning Positive value See UserDMM.h for function/range codes.
int DMMGetGrdVer(int nDmm) Remarks This function returns the DMM firmware version of the on-board controller. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Return Value Integer value. The return value is the version value or an error code. Value Meaning Positive Value Version Negative Value Error code Example firmwarever = DMMGetGrdVer(0); DMMGetHwVer SM2040 ; SM2042 ; SM2044 ; Description Get the hardware version of the DMM. #include "sm204032.
Remarks This function returns the DMM identification code. Each DMM has a unique ID code that must match the calibration file card_ID field in SM40CAL.DAT. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Return Value Integer value card ID code (serial number) or an error code. Value Meaning DMM_E_DMM Invalid DMM number.
DMMGetMax SM2040 ; SM2042 ; SM2044 ; Description Get Maximum reading history. #include "sm204032.h" int DMMGetMax(int nDmm, double *lpdMax) Remarks This function returns a double floating value that is the maximum (of the Min/Max function) value since either a function change, range change or call to the DMMClearMinMax function was made. This is only applicable to Primary read functions (those that are read using DMMRead, DMMReadStr or DMMReadNorm).
Value Meaning DMM_OKAY Valid return. Negative Value Error code Example char cBuf[64]; int status = DMMGetMaxStr(0, cBuf); DMMGetMin SM2040 ; SM2042 ; SM2044 ; Description Get Minimum reading history. #include "sm204032.h" int DMMGetMin(int nDmm, double *lpdMax) Remarks This function returns a double floating value that is the minimum (of the Min/Max function) value since either a function change, range change or a call to the DMMClearMinMax() function was made.
Description Returns the minimum as a formatted string. #include "sm204032.h" int DMMGetMinStr(int nDmm, LPSTR lpszReading) Remarks This function is the string version of DMMGetMin. It returns the result as a string formatted for printing. The print format is determined by the range and function. See DMMGetMin for more details. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero.
if(DMMGetRange == 0) printf("Lowest range selected"); DMMGetRate SM2040 ; SM2042 ; SM2044 ; Description Get DMM reading rate #include "sm204032.h" int DMMGetRate(int nDmm, double *lpdRate) Remarks This function returns a double floating rate in readings per second. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpdRate double * Pointer where the rate is saved. Return Value Integer value version code or an error code.
Example double f; int status = DMMGetSourceFreq(0, &f); DMMGetTCType SM2040 ; SM2042 ; SM2044 ; Description Get the themocouple type currently selected. #include "sm204032.h" #include "UserDMM.h" int DMMGetTCType(int nDmm) Remarks This function returns the Themocouple type currently selected. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Return Value DMM type Integer or an error code.
Return Value DMM type Integer or an error code. Value Meaning 2040 SM2040 is at nDmm slot 2042 SM2042 is at nDmm slot 2044 SM2044 is at nDmm slot Negative Value Error code Example int DMMtype = DMMGetType(0); DMMGetVer SM2040 ; SM2042 ; SM2044 ; Description Get DMM software driver version. #include "sm204032.h" int DMMGetVer(int nDmm, double *lpfResult ) Remarks This function returns the DMM software driver version, which is a double floating value.
Description Initialize a DMM. #include "sm204032.h" int DMMInit(int nDmm, LPCSTR lpszCal) Remarks This function must be the first function to be executed. It opens the driver for the specified DMM. The first DMM being 0, the second 1, etc... It also initializes the DMM hardware and does extensive self test to the DMM hardware. It then initializes the software and reads the appropriate calibration record for the respective DMM from the file specified by lpszCal.
Return Value TRUE, FALSE or an error code. Value Meaning TRUE Autoranging mode is selected. FALSE Autoranging mode is not selected. DMM_E_DMM Invalid DMM number. Example int autorange = DMMIsAutoRange(0); DMMIsInitialized SM2040 ; SM2042 ; SM2044 ; Description Get the status of the DMM. #include "sm204032.h" int DMMIsInitialized(int nDmm) Remarks This function returns the status of the DMM. If TRUE, the DMM has been initialized and is active.
Return Value Integer TRUE, FALSE or an error code. Value Meaning TRUE Relative mode is selected. FALSE Relative mode is not selected. Negative Value Error code Example int rel = DMMIsRelative(0); DMMLoadCalFile SM2040 ; SM2042 ; SM2044 ; Description Reload calibration record from file. #include "sm204032.h" int DMMLoadCalFile(int nDmm, LPCSTR lpszCal) Remarks This function is provides the capability to reload the calibration record.
Remarks This function is limited for servicing the DMM. It has no use in normal DMM operation.. See also DMMClosePCI() function. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Return Value Integer error code. Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code Example int status = DMMOpenPCI(0); DMMOpenCalACCaps SM2040 SM2042 SM2044 ; Description Calibrate the AC based in circuit capacitance function.
Remarks This function characterizes the Inductance measurement path and source, which is required prior to making inductance measurements. It should be performed within one hour, before using the inductance measurements. For better accuracy it should be performed more frequently. The Open Terminal calibration should be performed with the test leads open. The DMMOpenTerminalCal sweeps the inductance stimulus source across the full bandwidth, and makes measurements at several points.
DMMPolledRead SM2040 ; SM2040 ; SM2044 ; Description Tests the DMM for ready status, and returns the next floating-point reading. #include "sm204032.h" int DMMPolledRead(int nDmm, double FAR *lpdResult) Remarks DMMPolledRead polls the DMM for readiness. If the DMM is not ready it will return FALSE. If the DMM is ready with a new reading it will return TRUE, and the reading will be placed at the location pointed to by lpdResult. See DMMPolledReadCmd for more details.
Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Return Value DMM_OKAY if command accepted, else FALSE or an error code. Value Meaning FALSE DMM is busy and can’t execute a polled read command. DMM_OKAY Operation successful. DMM entered busy state Negative Value Error code Example int status = DMMPolledReadCmd(0); DMMPolledReadStr SM2040 ; SM2042 ; SM2044 ; Description If DMM is ready, return the next reading from the DMM formatted for printing.
DMMRead SM2040 ; SM2042 ; SM2044 ; Description Return the next floating-point reading from the DMM. #include "sm204032.h" int DMMRead(int nDmm, double *lpdResult) Remarks DMMRead reads the next result from the DMM, performs all scaling and conversion required, and returns the result as a 64-bit double-precision floating-point number in the location pointed to by lpdResult. It can read all the Primary functions (those that can be selected using DMMSetFunction() and DMMSetRange() ).
Remarks Read the next measurement from the DMM internal buffer, pointed to by an internal buffer pointer, and increment the pointer. Store the measurement as a 64-bit doubleprecision floating-point number in the location pointed to by lpdResult. See DMMArmTrigger() functions for more detail. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpdResult double * Points to the location which holds the frequency.
DMMReadCJTemp SM2040 ; SM2042 ; SM2044 ; Description Read cold junction temperature for thermocouple measurement. #include "sm204032.h" int DMMReadCJTemp(int nDmm, double *lpdTemp) Remarks Read the cold juncion temperature sensor for subsequent thrermocouple measurements. When measuring temperature using thermocouples it is necessary to establish a reference or cold junction temperaturem.
Remarks This is a Secondary function and the DMM must be in ACV measurement function, and a valid range must be set. A double-precision floating-point Crest Factor is stored in the location pointed to by lpdResult. This measurement is a composite function, utilizing several sub functions, and could take over 10 seconds to perform. See the Crest Factor measurement section of the manual for more detail. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero.
DMMReadFrequency SM2040 SM2042 ; SM2044 ; Description Return the next double floating-point frequency reading from the DMM. #include "sm204032.h" int DMMReadFrequency(int nDmm, double *lpdResult) Remarks If frequency counter is not engaged, select it. Make a single frequency measurement, and store the result as a 64-bit double-precision floating-point number in the location pointed to by lpdResult. See DMMFrequencyStr() for more details. Parameter Type/Description nDmm int Identifies the DMM.
Example DMM_OKAY Operation successfully completed. Negative Value Error code double Q; int status = DMMReadInductorQ(0, &Q); DMMReadMeasurement SM2040 ; SM2042 ; SM2044 ; Description Return a reading which is the result of DMMSetTrigRead operation. #include "sm204032.h" int DMMReadMeasurement(int nDmm, double *lpdRead) Remarks Signametrics This measurement reading function is designed to read triggered measurements from the DMM. It is a fast reading function.
Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpdRead double * Pointer to a location where the reading is saved. Return Value Integer value version code or an error code. Value Meaning TRUE Measurement was read into *lpdRead FALSE No measurement is available TIMEOUT Communication timeout. No reading available within 9s. OVERRUN Communication overrun. PC did not keep up with DMM transmission. Other Negative Value Error code.
DMMReadNorm SM2040 ; SM2042 ; SM2044 ; Description Take a reading that is in base value. #include "sm204032.h" int DMMReadNorm(int nDmm, double *lpdRead) Remarks This Primary read function is similar to DMMRead(). It returns a double floating-point reading. The returned value is corrected for base units. That is, it returns 0.3 for a 300 mV input and 1e6 for 1.0 MOhm. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero.
Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code Example double ptp; int status = DMMReadPeakToPeak(0, &ptp); DMMReadPeriod SM2040 SM2042 ; SM2044 ; Description Return the next double floating-point period reading from the DMM. #include "sm204032.
nDmm int Identifies the DMM. DMMs are numbered starting with zero. lpszReading LPSTR Points to a buffer (at least 64 characters long) to hold the converted result. The return value will consist of a leading sign, a floating-point value in exponential notation, and a units specifier. Return Value The return value is one of the following constants, or the string length is OK. Value Meaning DMM_OKAY Valid return. Negative Value Error code DMM_E_RANGE DMM over range error occurred.
DMMReadWidth SM2040 SM2042 ; SM2044 ; Description Return the positive and negative pulse widths. #include "sm204032.h" int DMMReadWidth(int nDmm, double *lpdPwid, double *lpdNwid) Remarks This is a Secondary function and the DMM must be in ACV measurement function, and a valid range must be set. It returns two parameters: positive and negative pulse widths. These parameters are stored as double-precision floating-point numbers in the location pointed to by lpdPwid and lpdNwid.
Return Value The return value is one of the following constants. Value Meaning TRUE DMM is done and buffer is ready to be read. FALSE DMM is not ready. Negative Value Error code Example double Buffer[10]; DMMTrigger(0,10); while( ! DMMReady(0) ); for(i=0; i < 10 ; i++) j = DMMReadBuffer(0, &Buffer[i]); DMMSetACCapsDelay SM2040 SM2042 SM2044 ; Description Set the measurement delay of AC based Capacitance. #include "sm204032.h" #include "UserDMM.
Remarks This Secondary function sets the AC peak voltage level for the AC based Capacitance measurement function. It actually sets an internal register to ldVols rather than setting the output level itself. This value is used on any of the AC Caps calibration and measurement. Following setting of this function, it is necessary to perform open calibration of the AC Capacitance ranges to be used.
Return Value Integer error code. Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code Example double reading; int I; DMMSetACVSource(0, 7.0, 1000.0); // source 7V and 1kHz DMMSetSourceMode(0, CLOSED_LOOP); // Closed loop mode for(I=0;I<100;I++) DMMRead(0,&reading); // update 100 times DMMSetAutoRange SM2040 ; SM2042 ; SM2044 ; Description Enable/Disable autorange operation of DMM #include "sm204032.
Remarks Setup the SM2040 for external hardware trigger operation. Following reception of this command the DMM enters a wait state. After reception of an external trigger edge of iEdge polarity, the DMM takes iSettle + 1 readings at the set measurement function, range, and reading rate; and stores the last reading in the in an internal buffer. This process is repeated for iSamples. This function is particularly useful in conjunction with a triggering instruments such as the SM4042 relay scanner.
Remarks This function should be used carefully since it modifies the capacitance function basic measurement parameters; the averages value, iAverage, and the number of points sampled, iSamples. This function is provided only for cases where it is necessary to improve measurement speed. When using this function keep in mind that the accuracy specification provided for capacitance is not guaranteed. Also, modifying these values could have profound efect on the operation of the function.
Error code. Negative Value Example DMMSetCJTemp(0, 22.5); DMMSetCompThreshold SM2040 SM2042 ; SM2044 ; Description Set the Threshold DAC level. #include "sm204032.h" #include "UserDMM.h" int DMMSetCompThreshold(int nDmm, double ldThreshold) Remarks This Secondary function sets the output of the Threshold DAC. To use this function, the DMM must be in AC volts. This function sets the detection threshold of the AC comparator. It is compared by the comparator to the AC coupled input voltage.
Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. fRange int The range to be set is a value between 0 and 7. See UserDMM.h Return Value Integer error code. Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code Example DMMSetCounterRng(0, COUNTR_320HZ); // Set counter to measure a frequency between 65Hz to 320Hz DMMSetDCISource SM2040 SM2042 SM2044 ; Description Set the DCI source output level. #include "sm204032.
Description Set the DCV source output level. #include "sm204032.h" #include "UserDMM.h" int DMMSetDCVSource(int nDmm, double ldVolts) Remarks This Secondary function sets the DC voltage source to ldVolts. The DMM must be in VDC_SRC for this function to execute properly. When the DMM is in VDC_SRC operation, and the DMMSetDCVSource is applied, reading the DMM (DMMRead or DMMReadStr) will return the measurement of the output voltage. This function acts on the main 12 bit source DAC.
ldShunt Return Value double Shunt resistance value. A value greater than zero and smaller the 200e6 (200 Mega Ohms) is allowed. Integer error code. Value Meaning DMM_OKAY Operation successfully completed. Negative Value Error code DMMSetExternalShunt(0, 100000.0); // Set shunt to 100kΩ Example DMMSetFuncRange SM2040 ; SM2042 ; SM2044 ; Description Set the DMM function and range. #include "sm204032.h" #include "UserDMM.
Description Set the DMM function. #include "sm204032.h" #include "UserDMM.h" int DMMSetFunction(int nDmm, int nFunc) Remarks This function sets the function used by the DMM. The table of values is defined by the VDC, VAC, IDC, IAC, OHMS2W, OHMS4W … definitions in the DLL header file. Not all functions are available for all DMM types. For instance the SM2042 has Capacitance while the SM2040 does not. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero.
Example int status = DMMSetInductFreq(0, 10e3); // Set source to 10kHz DMMSetOffsetOhms SM2040 ; SM2042 ; SM2044 ; Description Enable/Disable Offset Ohms operation #include "sm204032.h" int DMMSetOffsetOhms(int nDmm, BOOL bState) Remarks This function enables or disables the Offset Ohms compensation function. The default value is FALSE, or no Offset Ohms compensation. When TRUE the measurement rate is about 1/10th the set value.
Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. nRange int A pre-defined constant corresponding to the desired range. Return Value The return value is one of the following constants. Value Meaning DMM_OKAY DMM initialized successfully. Negative Value Error code DMM_E_RANGE Invalid DMM range value. Example status = DMMSetRange(0, _330mA); DMMSetRate SM2040 ; SM2042 ; SM2044 ; Description Set the DMM range for the present function.
Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. nRate int A pre-defined constant (RATE_*) corresponding to the desired reading rate. Return Value The return value is one of the following constants. Value Meaning DMM_OKAY DMM initialized successfully. Negative Value Error code DMM_E_RATE Invalid DMM reading rate. Example status = DMMSetRate(0, RATE_0P1); // Set to 0.
Description Set the resistance value to be synthesized #include "sm204032.h" int DMMSetResistance(int nDmm, double ldResistance) Remarks This function sets the value of the resistance to be synthesized. The DMM must be in Synthesized Resistance function for this function to be usable. The currently set external shunt resistor value effects the Synthesized Resistance operation. The ldResistance value must be between 10.0 to 0e6 (10MΩ). It is available with S/W versions 1.71 or higher.
Negative Value Example Error code DMMSetFunction(0, RTD); // RTD measurement function DMMSetRange(0, 1 _pt385); // Select RTD DMMSetRTD(0, RTD_4_W, 1000.0); // Set Ro = 1k Ohms DMMSetSensorParams SM2040 ; SM2042 ; SM2044 ; Description Set the cold junction temperature sensor equation parameters. #include "sm204032.h" int DMMSetSensorParams(int nDmm, double lda, double ldm, double ldb) Remarks Set the cold junction temperature sensor’s equation parameters.
reading is equal to the set voltage. However, for the ClosedLoop mode to update the source level, it is necessary to read the DMM multiple times. See DMMSetDCVSource and DMMSetACVSource for more details. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. iMode int Source adjustment mode: CLOSED_LOOP or OPEN_LOOP Return Value Integer error code. Value Meaning DMM_OKAY Operation successfully completed.
Description Set Thermocouple type. #include "sm204032.h" #include "UserDMM.h" int DMMSetTCType(int nDmm, int iType) Remarks This function selects the thermocouple type to be measured and linearized. It must be one of the following: B, E, J, K, N, R, S or T. Parameter Type/Description NDmm int Identifies the DMM. DMMs are numbered starting with zero. iTempUnits int The thermocouple type to be selected. This value can be set from BTyppe to TType as defined in the UserDMM.H file.
DMMSetTrigRead SM2040 ; SM2042 ; SM2044 ; Description Setup the DMM for mutiple Triggered readings operation. #include "sm204032.h" #include "UserDMM.h" int DMMSetTrigRead(int nDmm, int iSettle, int iSamples, int iEdge) Remarks Setup the SM2040 for external hardware trigger operation. Following reception of this command the DMM enters a wait state.
DMMSetTrimDAC SM2040 SM2042 SM2044 ; Description Set the Trim DAC level. #include "sm204032.h" #include "UserDMM.h" int DMMSetTrimDAC(int nDmm, int iValue) Remarks This Secondary function sets the Trim DAC to a value between 0 and 100. The trim DAC can be set to augment the main 12 bit DAC, whenever it is not automatically performed, such as in VDC and VAC source while OPEN_LOOP mode is selected. An example would be in DCI source, or when setting the Comparator Threshold.
be read using DMMReadTotalizer. A normal procedure would be to set the DMM to the ACV function, select voltage range, set the Threshold DAC, start the totalizer, wait for the time required, stop and read the total. The total number of events is limited to 1,000,000,000. The SM2044S product allows up to 90 kHz input, but reduces the resolution of the count. Parameter Type/Description nDmm int Identifies the DMM. DMMs are numbered starting with zero. Edge int Identifies the edge of the counter.
Description Terminate DMM operation (DLL) #include "sm204032.h" int DMMTerminate(int nDmm) Remarks Removes DMM number nDmm. This routine is used only where it is needed to terminate one DMM and start a new one at the same nDmm location. Otherwise, it is not recommended to use this function. Parameter Type/Description nDmm int Identifies the DMM to be suspended. Return Value Example The return value is one of the following constants.
DMM_E_DMM Example Invalid DMM number. double Buffer[64]; int state; DMMTrigger(0,64); while( ! DMMReady(0)); for(i=0; i < 64 ; i++) state = DMMReadBuffer(0, &Buffer[i]); DMMWidthStr SM2040 SM2042 ; SM2044 ; Description Return positive and negative pulse width in string format. #include "sm204032.h" int DMMWidthStr(int nDmm, LPSTR lpszPos, LPSTR lpszNeg) Remarks This Secondary function is the string equivalent of DMMReadWidth.
6.0 Maintenance Warning These service instructions are for use by qualified personnel only. To avoid electric shock, do not perform any procedures in this section unless you are qualified to do so. This section presents maintenance information for the DMM. Test equipment recommended for calibration is listed below. If the recommended equipment is not available, equipment that meets the indicated minimum specifications may be substituted.
Table 9-2. DC Voltage Test Step Range Input 1 2 3 4 5 6 7 8 9 330 mV 330 mV 330 mV 3.3 V 3.3 V 33 V 33 V 330 V 330 V 0V (short) 190 mV -190 mV 1.9 V -1.9 V 19 V -19 V 190 V -190 V Minimum Reading -8 µV 189.9787 mV -190.0213 mV 1.899898 V -1.900103 V 18.99834 V -19.00166 V 189.9833 V -190.0167 V Maximum Reading +8 µV 190.0213 mV –189.9787 mV 1.900103 V -1.899898 V 19.00166 V -18.99834 V 190.0167 V -189.9833 V 6.
3. Select the 4WΩ function on the SM2040, Autorange. Set the calibrator to 0 Ω. Be certain that the calibrator is set to external sense ("EX SNS" on the Fluke 5700A or “4-Wire Comp” on the 5520A). Allow the SM2040 to settle for a few seconds, and perform the Relative function. 4. Apply the following Resistance values to the V, Ω + & - terminals. Check to see that the displayed reading on the SM2040 is within the indicated range.
Table 9-5. Mid-Frequency AC Voltage Tests All inputs are a sine wave at 400 Hz. Step Range Input Minimum Reading 1 2 4 5 6 7 8 9 330 mV 330 mV 3.3 V 3.3 V 33 V 33 V 250 V 250 V 10 mV 190 mV 100 mV 1.9 V 1V 19 V 10 V 190 V 9.8650 mV 189.5950 mV 0.098735 V 1.897565 V 0.98327 V 18.97313 V 9.864 V 189.756 V Maximum reading 10.1350 mV 190.4050 mV 0.101265 V 1.902435 V 1.01673 V 19.02687 V 10.136 V 190.244 V Table 9-6. High-Frequency AC Voltage Tests All inputs are at 50 kHz.
6.7 AC Current Test The following procedure may be used to verify the accuracy of the ACI function: 1. If you have not done so, install the SM2040 and place the covers back on to the computer. Ensure that the computer has been on for at least one-half hour, with the covers on, before conducting this test. 2. Remove all connections from the SM2040 inputs. Select the ACI function, Autorange. 3. Apply the following AC currents to the I,4Ω + & - terminals.
2. Select the ACV function, autorange. Turn freq on. 3. Apply the following AC voltages to the V, Ω + & - terminals. Check to see that the displayed reading on the SM2042/44 is within the indicated range of readings. Table 9-9. ACV Frequency Counter Test Step Range Input Minimum Reading 1 2 3 4 5 6 330 mV 3.3 V 33 V 330 V 330 mV 33 V 33 mV, 40 Hz 330 mV, 40 Hz 3.3 V, 40 Hz 33 V, 40 Hz 250 mV, 100 kHz 25 V, 100 kHz 39.9952 Hz 39.9952 Hz 39.9952 Hz 39.9952 Hz 99.996 kHz 99.996 kHz Maximum reading 40.
iac 1.6 0.0 1.69 0.0 2w-ohm 1.27e+4 1256.0 110.0 0.0 0.0 0.0 0.0 0.0 ; IAC 3.3mA to 2.5A ranges, offset and gain 1.02402 1.03357 1.00513 1.0142 ; Ohms 33, 330, 3.3k,33k,330k,3.3M,33M,330Meg ranges, offset and gain 1.002259 1.002307 1.002665 1.006304 1.003066 1.001848 0.995664 1.00030 The first column under any function, e.g.,"vdc", is the offset term "b", expressed as a value proportional to analog-to-digital (a/d) counts. The second column is the scale factor term "m".
7.0 Warranty and Service The SM2040 is warranted for a period of one year from date of purchase. If your unit requires repair or calibration, contact your Signametrics representative. There are no user serviceable parts within the SM2040. Removal of any of the three external shields will invalidate your warranty. For inwarranty repairs, you must obtain a return authorization from Signametrics prior to returning your unit. 8.
