multiple DMM measurements in signalexpress

[rmats]

How to do multiple DMM measurements using Signalexpress. I want to use the same sensor and do sequential resistance and capacitance measurements using PXI 4072. Is this possible? Is it possible to reconfigure the DMM to take different type of measurements in a sequence?

[Mr.F]

You can add multiple steps in Signal Express and set one to execute after the other. The device will be configured for the measurement you specify in the DMM/Switch Acquire Step. Do you have the hardware and software?

[rmats]

Matt,

Thank you for the reply.

I thought it should do the same. But this what happens on my system. I add the step, NI_DMM/Switch Acquire, configure the DMM to measure 2-Wire resistance.

Then when I add a second step (for the purpose of acquiring capacitance) with NI_DMM/Switch Acquire, it would say no device available and the original DMM is greyed out.

Is this expected behavior and is there a workaround?

I have the following Hardware and Software.

Hardware: PXIe 1073 on a Desktop PC, PXI 4072, PXI 2550 with TB 2630 and TB 2631

Software: Licensed: Labview 8.2.1 and 8.5 | Signal Express 2.5

       Using: SignalExpress 2009 Evaluation

[Mr.F]

Hey,

Sorry, I think I spoke too soon; I had more than one DMM in my system and I accidentally selected two different DMMs. I saw the same thing you did and after a bit of investigation, the DMM driver initializes a session to the device and does not let go of that device until the Signal Express finishes. Since you have LabVIEW you could build a LabVIEW VI that initializes the DMM, takes the measurement and then closes the session to the device. You could create two Vis that do these two actions and use those as LabVIEW steps in Signal Express. There are examples in LabVIEW for basic DMM measurements in the example finder.