Labview continues polling PXI-4060 DMM in PXI-1010 chassis

[Havarti]

We have a PXI-4060 DMM in a PXI-1010 a chassis. Whenever the niDMM Read.vi is called, labview will continue to poll the DMM (the light on the PXI controller card keeps blinking) until the calling vi is exited as well as labview is exited. Anyone have the same situation? Everything works fine but I dont think it should keep communication open even when there are no VIs open.

Brian

[sead_suskic]

Brian,

The observed behavior is actually expected, and it is related to the implementation of niDMM Read.vi (and the niDMM_read() function in NI-DMM driver) specific to the NI PXI-4060. More specifically, the behavior is an optimization in the driver that makes subsequent calls to niDMM Read.vi faster as long as the measurement configuration parameters have not changed - relatively speaking, the first measurement on the PXI-4060 takes longer than subsequent measurements. In general, this behavior should not cause any issues in your system. If you need to, you can work around this behavior by using niDMM Read Multi Point.vi.

Sead Suskic
NI-DMM Software Group
National Instruments