Solution
If the error does not indicate any "Valid Choices", your NI data acquisition device does not support analog triggers. For NI 9233 and 9234, please refer to the the following article for information on how to trigger acquisition on these modules:
Can I Trigger an NI 9233 or NI 9234 Module?If the device is a simulated device, triggering is not supported for any device of any version of DAQmx.