Using digital output like enable for external load during Logging session.

[badfox]

Hello,
I am relatively new in SignalExpress 2015, and I have some difficulty in the management of the digital output.
In essence should I use a digital output P1.0 to enable a dummy load during a measurement session.
This output should go high ONLY during the DAQmx Acquire cycle ends when the P1.0 cycle must go low.
I read the tutorial and the forum but nothing.
How should I set the conditions for P1.0 output?

Thanks in advance.

[Stfn.fois]

Hi badfox,

I'm sorry but I really don't understand what's your goal...

Do you want to rise the digital output P1.0 of your DAQ as soon as your Acquisition ends? And what about the acquisition: what kind of acquisition are you talking about? Can you tell me your DAQ device model?

Thank you!

Stefano

[badfox]

Hi,
I am using USB-6212 with SignalExpress 2015.
I use an arbitrary waveform to control the discharge current of battery and in parallel I have a 1Hz read cycle that acquire two analog signal (voltage and current).
The arbitrary waveform controls the discharge current of the battery under test and the 1Hz read cycle of the two analog inputs serves to monitoring the current/voltage.
The start of recording cycle is manual (controlled by "RUN") while the end of the registration is automatic; when the battery voltage falls below 4V, using the recording options, i finish the logging.
I would use a digital output (es.P1.0) to control the battery to the load when I start recording and disconnect it from the load when I finish the acquisition cycle.

Example:
1) Start logging with "RUN" button of SignalExpress.
2) P1.0 -> High (battery connected to load).
3) Start cycle with arbitrary waveform generatione + voltage / current logging; this cycle ends When battery voltage going under 4V.
4) P1.0 -> Low (battery unconnected).
5) Stop logging.

I don't know how to program the P1.0 output as in steps 2) and 4).
Can you give me an example on how to control a digital output state at the beginning and at the end of a logging cycle?

Many thanks,

Fabio

[Stfn.fois]

Hi,

I think that what you want to do is not possible in SignalExpress. You can repeat the DAQmx generation under a condition... but the available inputs for the condition itself don't give us the possibility to stop the cycle according to the comparison of the signal to a threshold. There are only three possiblity for a conditional repeat execution mode:

- current iteration;

- date and time;

- duration.

regards,

Stefano