square wave digital signal

[eng.khalid]

dear all,

i am trying to generate two square wave signals where they are out-phase. i am struggling to feed the digital signals that have been generated to the daq system to open and close two valves through the mechanical relay. i have attached my file. Any help will be appreciated.

regards, 

Khalid

[RavensFan]

Try making your DAQ Assistant to be N samples rather than 1 sample.

Because is it 2 channels, 1 sample, it is looking for a 1-D array.  But you are giving it 2 channels, multiple samples which is a 2D array.

[eng.khalid]

thank you very much for your reply. I have done what you have mentioned above, but the problem appears form the external clock should be identified as i am using PXI 6229. i have tried to select different type of external clock but does not work. could you please guide me.

Khalid

[cbutcher]

It seems like you didn't do what RavensFan said - all you need to change (at least, to get it working) in your first VI is the sample mode in the Express VI (DAQ Assistant).

Double click on the Assistant to open the configuration, then change "Generation Mode" from "1 sample - on demand" to "N Samples".

I'd also suggest changing the number of samples to match your sampling settings at generation, and using only a single control (not two).

You can wire these values into the Assistant too, like this:

[cbutcher]

You can actually use just a single Digital Waveform generation too, if you want:

Note the snippets are saved with 2019, so you might not be able to open them. The VI I attached to the previous post is backsaved to 2018, which appeared to have been the source version.

[eng.khalid]

Firstly, I would like to thank you all for your help

The test rig that i am working on have a PXIe-1095 and I am using an M Series. National Instruments PXI-6229 Multifunction I/O Module to generate digital signals. It has been mentioned in the manual the device does not have an onboard timing engine for digital I/O. Therefore, i need to identify the clock source to send the digital signals. what I should to do in this problem. Please see a screenshot attached, I get this error.