Setting 6250 counter threshold

[John_P1]

Hi Eric,

The counter input terminal is set to /Dev1/AnalogComparisonEvent.  The analog trigger on the AI task is set to use Dev1/ai0 for the trigger source.  The counter counts the analog comparison event which is generated by the analog input on ai0.

Best Regards,

[AiR_GuNNeR]

Hi John,

That makes sense, but I guess the question is what if I use ai1 instead of ai0?  How does the counter know to map to ai1 instead?  I'm sure this is probably a dumb question, but something isn't clicking with me.

Eric

[John_P1]

You would specify to acquire on ai1 when you create your analog input task, and specify to trigger off of that channel when you configure the analog start trigger:

//Configure Analog Task
DAQmxCreateTask("",&aiTaskHandle);
DAQmxCreateAIVoltageChan(aiTaskHandle,<insert AI channel here>,"",DAQmx_Val_Cfg_Default,-10.0,10.0,DAQmx_Val_Volts,NULL);
DAQmxCfgSampClkTiming(aiTaskHandle,"",10000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1000);
DAQmxCfgAnlgEdgeStartTrig(aiTaskHandle,<insert AI channel here>,DAQmx_Val_Rising,<insert trigger level here>);
DAQmxSetAnlgEdgeStartTrigHyst(aiTaskHandle, <insert trigger hysteresis here>);

Best Regards,