Confused about number of analog tasks on cDAQ

[santo_13]

Jerry_X, some mistake in the math, still 14 slots x 4 channels results in only 56 channels and OP will be short of 8 channels.

[Jerry_X]

Doh, you are right! I don't know why I think 14 * 4 is 64, not 56. Maybe I didn't drink enough coffee this morning. 😅

In that case, to meet the channel requirement we will need 2 cDAQ-9179s and 2 NI 9469s (sync module). Using the sync module allows cross chassis synchronization which allow the user to put all the AI modules in the same DAQmx AI task, and DAQmx will take care of the all the synchronization on the backend.

[santo_13]

Does DAQmx channel expansion work across different cDAQ chassis or does the user has to maintain task per chassis and configure the sync?

I know that DAQmx channel expansion works across PXIe chassis with the Timing&Sync option.

[Jerry_X]

DAQmx channel expansion work across different cDAQ chassis in 2 cases

• Signal based: Every chassis connected has a NI 9469 module connected together as star or daisy chain
• Time Sensitive Network based: 9185/9189 (Ethernet cDAQ) chassis on the same subnet with all the network bridging element also being TSN capable

Then the user can have a single DAQmx task containing all the modules from different chassis.