How to Synch Multiple PCIe Cards to Capture Digital Inputs Simultaneously?

Updated Sep 7, 2018

Reported In


  • PCIe-6612
  • RTSI Cable


  • NI-DAQmx

Issue Details

I have an array of multiple digital sensors that generate TTL pulses when they detect physical fenomena.  The problem is how to synchronize two or more PCIe cards like the PCIe 6612, for example, to capture all the pulses from the array of sensors simulataneously.  I have used BNC connector blocks before, but the more sensors or cards I add to the array, the harder it becomes to sychronize all the tasks without any skew in the signals.

Is there a better approach in regards to hardware setup to sych multiple PCIe cards?


The best way to synchronize multiple PCIe devices is to connect them with a RTSI cable.  You can setup the tasks to use the internal clock as the master clock for all your counter input tasks to count the TTL pulses. Refer yourself to this example to understand how to program this kind of tasks in DAQmx

Counter Input Synchronization with 660x Timing and Digital I/O Device

By connecting the RSTI cable you can synch all the tasks to te master clock without any skew.

Additional Information

RTSI Installation guide


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