Hi Fausto,
Thank you for your response. Unfortunately, upgrading LabVIEW isn't an option for us at this time, due to some compatibility issues with another component in our instrument. I can try updating our MCC software, though. At the moment, we are using InstaCal v6.26.
The multiple DAQ tasks being the culprit makes sense, as this worked fine when we just used the analog channels. I can try to update our wiring to read the digital TTL signal as an analog signal instead and see if that helps.
Thanks,
Carrie