Synchronizing C Series Delta-Sigma Modules in Multiple cDAQ Chassis

Updated Aug 1, 2018

Reported In

Hardware

  • NI-9218
  • NI-9225
  • NI-9227
  • NI-9229
  • NI-9230
  • NI-9232
  • NI-9234
  • NI-9235
  • NI-9236
  • NI-9237
  • NI-9238
  • NI-9239
  • NI-9242
  • NI-9244
  • NI-9246
  • NI-9247
  • NI-9250
  • NI-9251
  • NI-9775

Software

  • LabVIEW

Issue Details

I have two or more C Series modules that have a delta-sigma ADC, each in their own cDAQ chassis. How can I synchronize these modules?

Solution

Unlike other C Series modules, modules with delta-sigma ADCs (DSAs) require synchronized sample clock timebases in order to achieve sample clock synchronization.


Since cDAQ Programmable Function Input (PFI) lines have a maximum bandwidth of 1 MHz, which is lower than the internal timebases of all DSA modules, PFI lines cannot be used to implement Sample Clock Synchronization between DSA modules on multiple cDAQ chassis.

In order to synchronize DSA modules, there are currently two potential solutions:
  1. Use a NI-9469 Chassis Synchronization Module in each cDAQ chassis to export timebases in a master-slave configuration
  2. Connect two or more Time Sensitive Networking (TSN)-enabled cDAQ-9185 or cDAQ-9189 chassis and utilize their time synchronization features to synchronize the timebases of C Series DSA modules. Data collected from these modules will still need to be adjusted for group delay. 

Additional Information

If you're not sure whether you require this type of synchronization, you can find a complete list of the C Series modules that need the NI-9469 or a TSN-enabled cDAQ-9185/cDAQ-9189 in order to be synchronized across multiple cDAQ chassis by looking at the "C Series Delta Sigma Devices" section of  C Series Device Groupings.

WAS THIS ARTICLE HELPFUL?

Not Helpful