pxi 6220 redefining terminal routes

[chassan]

Hello,

In MAX explorer, the pxi 6220 routes tab shows a direct route from PFI6 to the counter 1 gate (ctr 1 to be used for low freq counter) and an indirect route through counter 1 to PFI 4.  But from the terminal diagram for the card, it looks like PFI 4 IS the counter 1 gate.

However, in LabVIEW terminal rerouting VI, I can select PFI 6 as the source and PFI 4 as the destination (there is no option to select counter 1 input as destination), but the counter does not appear to be counting.  At the moment the input on PFI 6 is a "TTL" level square wave, but I don't get any counts.

Does anyone have any experience with this...any suggestions on what to try to determine where the problem is?

Best Regards,

Chris

[dansch]

Hi Chris,

To configure the input terminal of your counter to be a PFI line other than the default (PFI4 is the gate of CTR1 by default), you can simply use the CI.Freq.Term property node. To do this, place a DAQmx Channel Property Node down after creating the counter task, and navigate to Counter Input » Frequency » Input Terminal. You can then specify which PFI line to use as the input (for frequency measurement, the input is the gate of the counter). I have also attached a screenshot of what this looks like in LabVIEW. Hope this helps,

[chrishassan]

Hi Daniel,

Thanks for the ealier post...sorry it took me a while to get back to it.

The channel property node that only contains "Analog Input" and "General Properties"; no counter or digital properties.  I guess that's why I couldn't find the correct property...it isn't there!

I am trying to attach the code-of-interest to this message.  Please help.

By the way, I'm actually using a PXI-6221, not a PXI-6220.

Thanks in advance,

Chris

[dansch]

Hi Chris,

If you are unable to see properties in your property node, I would first check to see if you are filtering the properties according to the devices in your system. There is a KnowledgeBase article outlining the property filtering which can be found here.

Also, if you right-click the section of the property node where the property is displayed, you should see a selection at the bottom titled “Select Property…” If you click this, a browser should appear with all the properties of DAQmx Channel.

If you are unable to select the property by right-clicking on the property node, you can also navigate to View » Class Browser and select the DAQmx object library and DAQmx Channel class. Hope this helps,

[chrishassan]

Daniel,

Thanks for the help; my problem has been solved.

The PXI chassis that I'm working with contains two 4472B cards (analog inputs only) and one PXI-6221.  I had to right click the channel property node, select the "Select Filter..." option, and then check the PXI-6221 in the "Show Attributes for Selected Devices".  Initially, both 4472B cards were selected but the PXI-6221 was not.

It works very well now.

Best Regards,

Chris Hassan