viSci Posted June 27, 2019 Report Share Posted June 27, 2019 (edited) At my wits end with this... When 1588 timesync is running it appear to interfere with DAQmx AI timed tasks. I am seeing strange errors -200284 (buffer underrun) or -209836 (The devices in your task cannot be synchronized) when I start my DAQmx task with 1588 engaged. When I disable the 1553 master on my network or remove the 1588 driver from the cRIO everything works correctly. To simplify testing I am using a DAQmx example - Thermocouple - Continuous Input.vi to do my testing. I do not have any HW sync modules just plain C series AI modules so there should be no attempt to perform any AI clock slaving since this is a software only 1588 system. BTW I am using the latest 19.0 drivers and LV Dev. I also see the same behavior in 18.5. Your thoughts please... Edited June 27, 2019 by viSci Quote Link to comment
viSci Posted June 28, 2019 Author Report Share Posted June 28, 2019 (edited) Just in case someone else stumbles across this problem... It turns out the the cRIO-9056 has TSN capability built in so it will automatically try to slave the AI sample clock to a 1588 master if one is present on the network. In my case the master clock is not disciplined which wrecks havoc on the AI HW timing as it is only software based for the purpose of syncing the cRIO to the PC's clock for uniform relative accuracy. The solution to the is to use an obscure DAQmx property as follows... Add a DAQmx Channel Property Node to the task, select the General Properties >> Synchronization Unlock Behavior property and set it to Ignore Lost Sync Lock. Edited June 28, 2019 by viSci 1 1 Quote Link to comment
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