Startdelay in Position Mode

alex niebling

Intellectual 790 points

Hello guys,

i am using the Position Mode and i measured out the startdelay.

When i set the start command gMotorVars.RunPositionProfile = 1 it takes about 40 ms untitl the motor spins.

Attached Graph explaination:

When the SYNC = high then the gMotorVars.RunPositionProfile Variable = 1.

When RPM > 50 = high then Speed reaches 50 RPM.

Can you explain me why we sppend so much time?.

Thanks guys

over 7 years ago

0 Whitney Dewey over 7 years ago

TI__Guru 54195 points

Hello,

Is this while you're running one of the labs? Which one are you running?

Thanks,
Whitney

0 alex niebling over 7 years ago in reply to Whitney Dewey

Intellectual 790 points

Hello,

My base is the lab13b. My mainISR is about 150uS. The SpinTac Components are set every second mainISR ticks.

// Run the SpinTAC Components (ISR_TICKS_PER_SPINTAC_TICK = 2)
   if(stCnt++ >= ISR_TICKS_PER_SPINTAC_TICK) {
       ST_runPosConv(stHandle, encHandle, ctrlHandle);
       ST_runPosMove(stHandle);
       ST_runPosCtl(stHandle, ctrlHandle);
       stCnt = 1;
   }

Then the Motor must be start about 2*150uS + SpinTac processing Time.

Thanks Alex

0 Yanming Luo over 7 years ago in reply to alex niebling

TI__Guru** 116090 points

It's right, the motor takes some time to run from zero speed to target speed. You might change gMotorVars.MaxAccel_krpmps and gMotorVars.MaxDecel_krpmps to adjust the acceleration.

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Startdelay in Position Mode