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

407x

408x

NI-DMM/Switch Express VI

Supported

Unsupported

NI-DMM Soft Front Panel: Debug Driver Session

Supported

Unsupported

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: 

Behavior

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

Supported

Unsupported

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)

10000

Number of LC Measurements To Average Property:

 Default value

1

20

Capacitance Measurements: 

Overrange Behavior

Returns calculated measurement and overrange warning

Returns NaN and overrange warning

Offset Compensated Ohms Property:

Range Support

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

Supported

Unsupported

Restore Last External Cal Constants Function

Supported

Unsupported

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.