niDMM_InitExtCal

ViStatus = niDMM_InitExtCal(ViString Resource_Name, ViChar Calibration_Password[], ViSession *Instrument_Handle)

Purpose

The following operations are performed if the Calibration_Password is valid:

• Creates a new session for external calibration to the device you specify for the Resource_Name parameter.
• Resets the device and prepares the EEPROM for new calibration coefficients.
• Returns a ViSession handle that you use to identify the instrument in all calibration adjustments and post-adjustment verification steps.

Notes

The NI 4050 and NI 4060 are not supported. Refer to the NI 4065 6½ Digit DMM Calibration Procedure, the NI 4070/4072 6½ Digit FlexDMM Calibration Procedure, or the NI 4071 7½–Digit FlexDMM Calibration Procedure before using this function. This function creates a new session the first time you invoke it for a device. If you call this function on the same resource, an error is returned. You should use niDMM_CloseExtCal to close a session obtained using this function.

After opening a calibration session, the device cannot take valid measurements using this session until the device has been properly adjusted. Once the adjustment phase is complete, you can use this session to verify the new calibration constants. After verification, you have the option of saving the new calibration constants or reverting to the previous calibration constants by specifying the Action parameter in niDMM_CloseExtCal.

If you encounter a fatal error such as a power failure or system crash while performing an external calibration, you can call niDMM_RestoreLastExtCalConstants to return the device to a usable state.

Parameters

Input
Name	Type	Description
Resource_Name	ViString	Contains the Resource_Name of the device to initialize. The Resource_Name is assigned in Measurement & Automation Explorer (MAX). Refer to Related Documentation for the NI Digital Multimeters Getting Started Guide for more information about configuring and testing the DMM in MAX. Valid Syntax: NI-DAQmx name DAQ::NI-DAQmx name[::INSTR] DAQ::Traditional NI-DAQ device number[::INSTR] IVI logical name Caution  All IVI names for the Resource_Name, such as logical names or virtual names, are case-sensitive. If you use logical names, driver session names, or virtual names in your program, you must make sure that the name you use matches the name in the IVI Configuration Store file exactly, without any variations in the case of the characters in the name.
Calibration_Password	ViChar[]	Specifies the password required to enable external calibration functionality. The maximum password string length is eight characters, excluding the termination character. "NI" is the factory-default password.
Output
Name	Type	Description
Instrument_Handle	ViSession	The session handle that you obtain from niDMM_InitExtCal. The handle identifies a particular instrument calibration session.

Return Value