Odd PCI-6509 behavior, all pins high

[KNRO]

I have PCI-6509 96 Channel Digital I/O which was working fine for the last couple of months as far as generating values (and can still generate values properly) but when I started to use some ports to read TTL signals, I encountered an odd problem, all pins are set to high. (and I mean ALL, even those not conneted to anything).

I checked the connector block myself, but all voltages were 0.06v or less, so it never made sense. I tried to write 0 to all the ports, and when I ran the read operation again, I got 0. Sounds like that solved the problem? No!

In fact, I had an infinite loop for the read operation, and I can see the value transitioning automagically from 0x00 to 0xFF in a matter of 15 or so seconds! I exhuasted all efforts in trying to reset the device, used the programmable power-up states to set them all to zero (which I think is the default), but with no avail.

Initially, I thought it was a problem with some of the wires in the connector block, but after I removed a few lines here and there, I didn't see any chages. I removed the cable from the PCI card and it's still behaving the same! So it's something internal to the board. I switched the board between two computers, same identical behavior.

As I said earlier, the card is still capable of generating values. It looks like that I'll end up sending the card for repair, but I was wondering if anyone faced a similar issue before doing so.

[Kenn_N]

Hey KRNO,

Thanks for contacting National Instruments support.  The 6509 does have programmable power-up states as stated in the manual, and the default power up state in an input (high Z) state.

The manual states:

At power-up, the output drives on the NI 6509 are disabled. All lines are
user-configurable for high-impedance input, high output, or low output.
User-configurable power-up states are useful for ensuring that the NI 6509
powers up in a known state.

To use MAX (recommended) to program the power-up states, select the
device and click the Properties button. Refer to the software
documentation for information about how to program the power-up states
using NI-DAQ with LabVIEW or other National Instruments application
development environments (ADEs).

If you device is not functioning in this way, which it sounds as though it is not, I would call in to support to facilitate an RMA after speaking with an Appilcations Engineer.

Regards,