Behavioral Differences Between The PXI-407x and PXIe-408x DMMs


The table below identifies the notable behavioral and functional differences between the PXI-407x series, including the PXI-4070, PXI-4071 and PXI-4072, and the PXIe-408x series, including the PXIe-4080, PXIe-4081 and PXIe-4082. This table is not an exhaustive list, however it can serve as a resource when upgrading DMM hardware, or creating a modular application that functions with both DMM families. The Content of the table is accurate as of NI-DMM 17.5 and is subject to change without notice over the lifetime of each family.

For more information on the PXI-407x or PXIe-408x DMMs please see the NI Digital Multimeters Help.




NI-DMM/Switch Express VI



NI-DMM Soft Front Panel: Debug Driver Session



Frequency Voltage Range Property: 

Auto Range Settings*

-1 (On) : Supported (Default)

-2 (Off) : Supported

-1 (On): Unsupported (Default is 50)

-2 (Off) : Unsupported

Trigger Latching Behavior

If the device is not waiting for a trigger and then receives a trigger it will latch the trigger and then immediately "consume" it as soon as the DMM is armed to receive a trigger.

If the device is not waiting for a trigger, all triggers sent to the device are ignored and lost.

Trigger and Sample Trigger: 

Default Polarity

Falling Edge

Rising Edge

Trigger and Sample Trigger: Use

Trigger and Sample Trigger must have the same slope polarity (rising or falling), and, unless one is set to immediate, they must both have the same source.

Trigger and Sample Trigger may have different sources with different slope polarities

Send Software Trigger Function: 

Behavior when the board is not in running state

Unsupported: Trigger is ignored

Unsupported: Error thrown

Initiate Function: 

Calling the function twice in a row

The driver will abort the first initiated acquisition and initiate again.

Driver will abort the previous acquisition and initiate again only if the first acquisition has completed.  Otherwise an error will be thrown.

Get Aperture Time Info Function: 


Returns the aperture time exactly as the user input the value.

Returns the aperture time after it has been coerced to a multiple of the ADC clock period.

Get Measurement Period Function



Fetch VIs: Maximum Time (msec) property: 

Behavior after Acquisition Completed

If the acquisition is done, fetch returns a timeout error ASAP rather than waiting the timeout value.

 In simulation, the function waits the full amount then times out.

The function waits until the full timeout has passed before returning an error. 

This is consistent in both real and simulated devices.

Input Resistance Property: 

Valid values

4071: Coerces user input value up to next largest valid value.

4070/2: Coerces user input value up to next largest value and errors out if that value isn't valid for the specified range

Errors if the user's value isn't valid for  the specified range.

(No rounding is performed)

Buffer Size Property: 

Default value

1000. Applies to all modes

(Property node returns -1)

100000. (Property does not apply to waveform mode)

Number of Averages Property: 

Maximum Value

2147483647 (Maximum integer for an I32)


Number of LC Measurements To Average Property:

 Default value



Capacitance Measurements: 

Overrange Behavior

Returns calculated measurement and overrange warning

Returns NaN and overrange warning

Offset Compensated Ohms Property:

Range Support

Coerces value to "Off" for resistance measurement ranges ≥100kΩReturns error if property is set  to "On" for resistance measurement ranges ≥100kΩ

Waveform Points Property: 

Continuous Waveform Acquisition setting*

0 (Continuous Waveform Acquisition): Unsupported

0 (Continuous Waveform Acquisition): Supported

Waveform Mode:

DC Noise Rejection Property

All DCNR types can be used in waveform mode.  

(Note that the sampling frequency may need to be reduced to use some DCNR settings)

Only "Normal" DCNR type can be used in waveform mode regardless of sampling rate.

Get Cal Count Function



Restore Last External Cal Constants Function



Set Cal Password Function: 

Password character limit

Limited to 4 characters. Longer passwords are truncated to 4 characters.

Limited to ~32 characters. Longer strings will return an error.

Revision Query Function: 

Firmware Revision output

Returns letter revision in "rev X" format.

Returns revision in "YYDDMMHH" format.


*Users enter the Numeric value shown which represents the state shown in parenthesis.

Additional Resources: 


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