Configuring PCI-6509 in DAQmx

[jonnnnnnn]

Hello,

We are planning to use a PCI-6509 for Change of State detection. Our system will receive a signal on a line from a source and then relay it to another system. We intend to do this on Linux using the ANSI C DAQmx drivers.

The manual states that the card is software configurable. I have been looking at the DAQmx and think I've understood the concepts of tasks/lines/channels/ports.  I can set the edge detection for change of state, by following the examples provided.

We need to make sure two things happen on our output.

1) The default state of the line is high (applogies if I haven't got the terminology quiet right), 5V. When we send a output down a line we need the signal to drop to 0V (or as good as).

2) The output signal pulse width needs to be at least, but ideally, 500ns.

Is it possible to configure the card to do this?

If it is could someone provide some hints on where to look in the DAQmx drivers/a link to an appropriate example, it would be a great help.

(Don't mind working stuff out myself, but there's a lot to wade through and it's tricky to know where to start)

Thanks

[jonnnnnnn]

Found a couple more things (incase anyone reads and is looking for the same answer)

I believe the DAQmxSetDOInvertLines can set the high = false / low = true state, if it is passed the value TRUE.

The DAQmxSetDIFltrMinPulseWidth can be used to set the minium pulse width on an input, but I still haven't found a similar function for an output.

[Dennis_Knutson]

Are you trying to change the default power up state? That would be DAQmxSetDigitalPowerUpStates. The property you mention does not do that. If set, what it does is output a high when programmed to be off and output a low when programmed to be on.

There is no setting for output pulse width. As you can see from the specs, the card is software timed. About the best timing you can expect is going to be around 1ms.

[jonnnnnnn · Accepted solution]

Hi, thanks for replying.

No I wasn't tying to change the power up state. I think the Invert Lines property will do what I want in terms of getting the signal the right way round.

>About the best timing you can expect is going to be around 1ms.

Ok, useful info. Thanks. It'll do what we need at that speed.