Agilent 34401A External Trigger VI using 6508 to send to 1 shot pulse

[chiuyu]

Hi

I want the Agilent 34401A DMM to be triggered externally using LabVIEW.  I hardwired the DMM externally and ran the VI : Combo_Pulse_6508_DMM1.vi.  The DMM was triggered externally.  However, I did not connect the error out of the DMM to the error in of the DIO because the loop always hangs in there.

I am told that I should create my VI with all the error out connected to the error in.  The VI should look very similar to the one I attached, Combo_Desired_Pulse_6508_DMM1.  When I ran my VI, there was no error message coming out of the DIO device, but the loop hangs in the "Read Measurement Sub VI." Yet, I noticed that when I used "Measurement and Automation Explorer" to check the status (test pannel) of my DIO device, there was an error showing up when I turn on and off certain pins of the DIO device.  The message says:

-"10613 badChanDirError The specified channel does not support the specified transfer direction, or you have performed an operation on a digital port or line configured for the opposite direction"

I really don't know how to debug it.  Could someone please look at my VI and give me a hand?

Thank you

[Hal_L]

Hi,

It sounds like you may have the port configured for digital input when you are trying to perform digital output. You can change the port direction by going to Measurement and Automation Explorer (MAX).

1. Select your device
2. Open Test Panels
3. Select your desired port
4. Select "all output"

I also would like to point out that you have a DAQmx task name constant wired into a Traditional NI-DAQ (Legacy) function. This could also cause you to run into problems. If you are trying to perform simple digital output, the best way is to use one of the shipping examples that come with LabVIEW. There are examples available using the DAQmx driver (Recommended) and Traditional NI-DAQ (Legacy).

The DAQmx Digital Output Examples are located in: Help>> Find Examples >> Hardware Input and Output >> DAQmx >> Digital Generation. I recommend taking a look at the Write Dig Port.vi.

The Traditional NI-DAQ (Legacy) Examples are located in: Help>> Find Examples >> Hardware Input and Output >> Traditional DAQ >> Digital Input and Output >> 8255. I recommend taking a look at the Write to 1 Digital Port.vi.

I hope this information helps you with your application.

Regards,

Hal L.