Solution
In order to use digital triggering with any task in a CompactDAQ (cDAQ) chassis, you must have a parallel digital input module in order to gain access to the Programmable Function Interface (PFI) lines they provide.
- If you have a cDAQ-9172, you must place the module in slot 5 or 6. These are the only two slots that have access to the PFI lines on this chassis.
- For the cDAQ-9173, cDAQ-9174, cDAQ-9178, cDAQ-9179, cDAQ-9184, cDAQ-9188 and cDAQ-9188XT, they do not have slot restrictions; you may use the digital module in any slot to obtain access to the PFI lines.
- As an exception to the rule, the NI-9205 and NI-9206 analog input modules support using an external analog trigger. This line can be accessed by the chassis (even the NI-9172) from any slot.
Note:
- The cDAQ-9177, cDAQ-9178, cDAQ-9179, cDAQ-9188 and cDAQ-9188XT have two built-in PFI lines, so if no more than two trigger lines will be required, there is no need for a digital module.
- The cDAQ-9189, has one built-in PFI, that can be used for this purpose.
To learn more about how to use a digital trigger in a task and how to configure it refer to NI-DAQmx Data Acquisition Triggering Techniques Using LabVIEW.