Triggering a C Series Module Using a Signal from a PCI Card

Issue Details

I want to measure analog signals using the NI-9775 and use the start trigger signal from the PCI-6115 PFI0. However, when I configure the PCI-6115 PFI0 as a digital trigger on the rising edge, an error occurs, and the NI-9775 does not acquire data. Why does this happen?

Solution

The measurement fails because the PCI-6115 and the NI-9775 do not share the same backplane. Therefore, you cannot route the PCI-6115 PFI0 signal to trigger the NI-9775 directly.

To work around this limitation, you can use one of the following methods:

• Use the cDAQ chassis PFI0: Input the digital trigger signal directly into the PFI0 of the cDAQ chassis to trigger the acquisition.
• Bridge the trigger signal: Connect another PFI port from the PCI-6115 to a PFI port on the cDAQ chassis, and input the digital signal there to trigger the acquisition.

Additional Information

PCI-based devices do not share a backplane with C Series modules installed in a USB cDAQ chassis. The USB cDAQ chassis connects to a host PC via USB, and the C Series modules interface directly with the chassis through a dedicated internal bus.