Generate 1khz signal on cdaq NI 9476

[RichC]

wishing to generate a 12v square wave using the cdaq chassis cDAQ-9178

Plugged in is a 32channel sourcing output card NI 9476

Frequency of square is 1Khz

The output card only has software timing

Simple what best option to generate this with the given hardware

Software platform is Labview 2009

[MarkGrot]

Hardware timed digital input/output is not currently supported on cDAQ chassis for modules with >8 lines.  I strongly encourage you to use the Contact NI->Product Feedback link to request this feature. 

With software timing you won't be able to reach 1kHz.  Performance is highly system dependent.  You are likely to see a maximum software timed digtal output write of around 800-1,000Hz which puts your frequency at half your goal (because you have to write high and low).  Even then the frequency of your signal would vary greatly.

[MarkGrot]

I'd like to provide an update to this thread for anyone still following it or who finds it through search.

In DAQmx 9.3 we added support for hardware timed digital on what were previously called static modules (>8 lines) in newer Compact DAQ chassis. The max rate is module dependent, check the module specifications for details (for example, the NI 9476 has a max rate of 2kHz). The names for modules in the documentation changed as well. Correlated (<= 8 lines) is now Parallel. Static (>8 lines) is now Serial.

There are a few restrictions with this new support:

1. Hardware timed digital tasks with serial modules are not supported on the cDAQ-9172. It is supported on all other cDAQ chassis.

2. You cannot use parallel and serial modules together in the same hardware timed task.

3. You cannot do both static and hardware timed tasks at the same time on a single serial module.

4. You can only do hardware timing in one direction at a time on a bidirectional serial module (NI 9403).

See the Digital I/O Considerations for C Series Devices in the DAQmx help for more information.