Can I Have Multiple cDAQ or cRIO Chassis on the Same DAQmx Task?

Updated Apr 18, 2024

Reported In

Hardware

  • CompactRIO Chassis
  • CompactDAQ Chassis

Driver

  • NI-DAQmx

Issue Details

I have several cDAQ chassis and a cRIO chassis with DAQmx functionality (e.g. cRIO-904x). Can I have these chassis on the same DAQmx task?

Solution

Yes, as long as the cDAQ and cRIO chassis are both TSN (Time Sensitive Networks) sync enabled. It is important to notice that multidevice tasks which include a cRIO are only supported between one cRIO and a network of cDAQ's and/or FieldDAQ's, that is, multidevice tasks are not supported between two or more cRIO chassis. See Additional Information for more resources on TSN.

These chassis can be put on the same task using channel expansion over multiple chassis, as seen in Figure 3 of the How to Achieve High-Accuracy Measurements With NI-DAQmx-Based TSN Devices white paper. If your system has DSA (Delta Sigma Analog-to-Digital converter) modules, your code will require post-process resampling for accurate synchronization.

Additional Information

TSN, or Time Sensitive Networks, is a communication standard built on top of the Ethernet standard. It allows for synchronization of enabled devices to within 1µs. TSN requires that there is a direct connection between the Network Interface Controller (NIC) and the timing source on the chassis, so only certain NI controllers currently have this functionality. Learn more about TSN on the NI TSN Forums