How to configure control lines as extra data lines on a PCI-6534?

[WilcoFan]

I am trying to configure an output control line as an extra data output on a PCI-6534.  I can successfully control the data I/O lines, but when I try the same approach to control any of the output control lines (PFI4 - 7), nothing happens (the line appears to be in a high-impedance state).  Attached is some simple LabView code that works for writing a data line but not for writing a control line.  From reading the manuals and the help material, it seems that all I need to do is do a write to the desired port5 line, but this doesn't work for me.  I've also tried refering to the line using the "Dev1/PFI4" naming syntax, but that hasn't worked either.

Any ideas?

[John_P1]

Hi WilcoFan,

The code seems OK to me, unfortunately I don't have a 6534 handy to verify that it works (although I can track one down if necessary).  What are you driving with the 6534?  Have you tried configuring the line as Open Collector and connecting the CPULL line to 5V?

-John

[WilcoFan]

Hi John,

Right now, I have the 6534 connected to a NI SCB-68 terminal block.  I am monitoring signals using an oscilloscope with 1 MOhm input impedance.

When I configure the line as open collector and connect the CPULL line to 5V, the port 5 control line stays at 5V when I try to write it to 0.  This seems to be the same type of behavior I saw when the line was configure as active drive -- the control line does not respond and appears to be high impedance.

Any other ideas?

Thank you for your help,

Lance

[John_P1]

This is quite interesting, it sounds like you might have damaged hardware that requires repair.  Before going through an RMA, could you try the following and let me know how it goes:

1.   Could you try writing to the lines through a Test Panel in Measurement and Automation Explorer (MAX)?

2.  Could you try writing to the entire port at once instead of just a single channel?  I would use the Write Dig Port.vi example that can be found through the LabVIEW Example Finder (Help >> Find Examples...).

3.  There is another example called Write Dig Chan.vi--I would try this one as well.

If you still are unable to write to the control lines, I would recommend to contact NI by phone since it sounds like the board may require a repair.

Best Regards,

John

[WilcoFan]

Here are the results of these attempts:

1) I was not able to write to any of the port5 lines using the test panel.  I was able to successfully read using port4 (the control inputs) using the test panel (I'm not sure if that tells us anything, but I tried it while I was experimenting with the test panel anyway).

2) Using the Write Dig Port.vi example to write to port5 did not work.

3)  Using the Write Dig Chan.vi example to write to port5 did not work, either.

One other thing I should mention is that I have another VI that will successfully export the sample clock to PFI4 on this 6534 card.  I'm not sure what that tells us about the state of the 6534 hardware but thought I should mention it.

I actually have another 6534 card I can try.  If that one works, I think we can confidently say it is a hardware problem with the first 6534 card.  I'll let you what I find out using the second card.

Thanks for your help,

Lance

[WilcoFan]

I've completed the experiment with the second PCI-6534 card.  Using the second card, I still can't write to port5 using the test panel, either example VI, or my own VI.  I also tried switching the 6534 to a different PCI slot to no avail.  I haven't tried switching the cable or the terminal block, but since I can successfully export the sample clock on PFI4, I know that at least the connection for PFI4 between the card and the terminal block screw terminal is good.

Could it be an issue with the version or installation of DAQmx?  Should I try using traditional DAQ?

Thanks,

Lance