Help with PXI-6509

[tward]

We are replacing our PXI-6508 with PXI-6509 boards, but can't seem to get them to act like the older boards.

I have set the PXI-6509 power-up states in MAX to all channels high and tristate disabled.

When I test the board in the test panel under MAX it doesn't act like I think it should.

For testing I have a piece of wire connected to Port 0: Channel 0 (Pin 47) and while watching the test panel I touch the other end of the wire to GND (Pin 50) the LED goes out, but when I remove it from the GND the LED doesn't come back on.

The other thing I notice is if I reset the board and don't have the test panel running then put a meter on Pins 47 and 50 I get 5 volts.  If I again ground Pin 47 to Pin 50 the voltage drops to around 0 volts (like it should) and when I remove the ground end it returns to 5 volts (like it should).  But if I do this while the test panel or my software is running it will drop to 0 volts and stay there.  If I touch the end of the wire connected to Pin 47 with my finger the LED will come back on but the voltage stays at 0 volts.

What do I need to do to make the PXI-6509 board act like the PXI-6508.  I was hoping the move to the newer board would be transparent to my software.

I am using NI-DAQmx v8.7.1 and C#.

Tom

[Bueller]

Hi Tom,

In order to have a better idea how the device is working. I recommend setting one port as an output and another one as input, and connect the output port to the input.

The following discussion forum might be of interest to you as well.

http://forums.ni.com/ni/board/message?board.id=250&message.id=36111&requireLogin=False

Regards,

Faris A

[tward]

Faris,

Hooking the inputs from Port 0 to the outputs from Port 1 works, but what I'm trying to do is like on the older 6508 is have the channels come up in a high state (5 volts) when the unit is powered up and then ground the channels to change the state (0 volts).  But when the channel is removed from the ground the state stays at 0 volts instead of returning to 5 volts like I think it should.

Does this not work on the 6509 like it did on the 6508?

If the "Test Panels" is NOT running and the board is reset (or just powered up) I can ground the channels and they will return to 5 volts when the ground is removed.  When the software is running it will not do this.

Tom

[tward]

Faris,

Does the 6509 use internal pull-up/pull-down resistors on the digital I/O lines?  Do we have to add our own pull-up resistor to each line?

Tom

[Bueller]

Tom,

The 6509 doesn't have internal pull up/ pull down resistors. Here is the list of devices that use internal resistors and their values.

As far as reading the input on the 6509, if I may ask, how are you able to read the inputs when the "Test Panels" is not running?

Regards,

Faris A

[tward]

Faris,

I'm using a volt meter to read the voltages off the channels.

OK so the 6509 doesn't work exactly like the 6508.  We'll have to add pull-up resistors to each channel.

Thanks for your help...

Tom

[OttoMate]

Hi - Ran into the same issue on the 6509, but unable to understand why is Test Panel behaving different? Is it not the Test Panel where the initial state(s), whether tri-state/low/high, constitute initial states of the I/O?

[LDowning]

It looks like this thread has been inactive for a few years. You may want to consider creating a new question to get some discussion from the community.