Generate Finite Pulse Train according to specific positions

[BTCbeubé]

Hello NI community,

We have an application that requires pulse generation at very specific position.

First of all, I am using NI USB-6341 OEM, an Optical linear encoder system RGH24X30A00A (Signal period is 4um, Resolution is 1 um) and a Camera receiving the triggers ( I can't disclose manufacturer/model number) 

disProf : Physical distance between triggers. 

startPosition :  Physical position where the trigger pulse train must begin.

nProf : Number of trigger contained in the pulse train.

The goal is this : 

from currentPos, the machine travels to startPosition where the Finite pulse train begins.

from startPosition, every disProf distance should have a trigger generated.

There is nProf amount of disProf

I am using DAQmx C functions this way : 

    errCode = DAQmxCreateCOPulseChanTicks(m_3DTriggerTask,
                                          TRIGGER_3D_COUNTER,
                                          "",
                                          ENCODER_Y_PIN_A,
                                          DAQmx_Val_Low,
                                          disToStartCnt,
                                          highPulses, 
                                          lowPulses);
    if (DAQmxFailed(errCode))
        Log << err << CURRENT_FUNCTION << " Can't create 3D trigger output channel. Error " << errCode << endl;

    errCode = DAQmxCfgImplicitTiming(m_3DTriggerTask, DAQmx_Val_FiniteSamps, nProfHw);
    if (DAQmxFailed(errCode))
        Log << err << CURRENT_FUNCTION << " Can't set continuous mode for clock. Error " << errCode << endl;

Now to the issue ; 

the DAQmxCreateCOPulseChanTicks methods uses one phase of the encoder as tickbase input (ENCODER_Y_PIN_A), there's a lot of noise in our environnment on a single phase of the encoder and that makes the NI board behave not like we expected.

I am looking for DAQmx C functions that could take in the counter associated with the encoder decoding as input for generation of trigger pulse.

Thank you for your help.