DAQ System Hanging Up/Monitoring Read Buffer

[diarmaede]

Hi All,

I am collecting data using two SCXI chasses with 1120 amplifier modules and SCXI 1112 thermocouple modules.

I am monitoring 12 input voltages and 4 thermocouple inputs.

I have set the samp,e rate to 2500S/s, and I am letting the software figure out how many samples to take each measurement.

Most of the time, the system runs fine, at about a 16ms loop time.  However, every few seconds, the system will hang up for ~500ms between readings.  Any thoughts as to what might cause these hangups?

I wonder if I am overflowing the read buffer.  Could that result in this type of behavior?  I think there is a way to monitor the read buffer, but I forget how to do it.  Can anyone tell me how to do that?

Many thanks.

[AdnanZ · Accepted solution]

You can monitor the read buffer by using the DAQmx Read Property Node and choosing Status->Available Samples per Channel.

[diarmaede]

Hi Adnan,

Thanks for the help!  I am now monitoring available samples.

I have realized that the problem is not in that buffer.  I only get the problem when I have the "Logging" function turned on so the program is writing data to a text file.  I will look into that issue by monitoring the write buffer to see if that is what is overflowing.

[AdnanZ]

I am not sure about your architecture but hope you are using a producer/consumer design pattern. You can find this by going to File -> New.. and browse down to Producer Consumer Design Pattern (Data)

[diarmaede]

Aha!  Someone else took a picture of the Producer/Consumer Design Pattern, but I did not realize it was a standard template.  This is EXTREMELY helpful.  THANKS!