Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Basic Motor Setup
87
If not getting the proper frequency range, double check the setting of I7m03 that sets the PFMCLK
frequency. Also check the value of Ixx69 that determines the maximum frequency (O100 frequency) at
this PFMCLK frequency.
frequency. Also check the value of Ixx69 that determines the maximum frequency (O100 frequency) at
this PFMCLK frequency.
Executing the Closed-Loop Test
Next, close the loop with a J/ command. The reported position should hold steady, and the reported
velocity should be zero. Set up yotheur jogging I-variables Ixx19 to Ixx22 to get the speeds and
accelerations needed. Issue a J+ command; count up at the rate specified by Ixx22 (watch the units).
Issue a J- command; count down at this same rate.
Now that what PMAC considers to be closed-loop moves are being executed, the servo loop gain
parameters are important. The easiest way to monitor performance is with the position window in the
PMAC Executive Program, configured to display position, velocity, and following error for the current
motor. More detailed analysis can be done with the data gathering plots.
velocity should be zero. Set up yotheur jogging I-variables Ixx19 to Ixx22 to get the speeds and
accelerations needed. Issue a J+ command; count up at the rate specified by Ixx22 (watch the units).
Issue a J- command; count down at this same rate.
Now that what PMAC considers to be closed-loop moves are being executed, the servo loop gain
parameters are important. The easiest way to monitor performance is with the position window in the
PMAC Executive Program, configured to display position, velocity, and following error for the current
motor. More detailed analysis can be done with the data gathering plots.
Troubleshooting the Closed-Loop Test
When troubleshooting these jogging moves, it is important to note what PMAC thinks the motor is doing
based on the pulse feedback compared to what the motor is actually doing. For example, if the motor has
stopped, but you see through the position window that PMAC keeps counting position, the motor has
probably stalled. Possibilities here include excessive velocity command, excessive load, and resonance
problems. However, if PMAC is also reporting a stop, something in the PMAC simulated loop has failed,
probably causing a shutdown on excessive following error. The main possibilities here are values set too
low for Ixx30 proportional gain, Ixx32 velocity feedforward, or Ixx69 output limit.
based on the pulse feedback compared to what the motor is actually doing. For example, if the motor has
stopped, but you see through the position window that PMAC keeps counting position, the motor has
probably stalled. Possibilities here include excessive velocity command, excessive load, and resonance
problems. However, if PMAC is also reporting a stop, something in the PMAC simulated loop has failed,
probably causing a shutdown on excessive following error. The main possibilities here are values set too
low for Ixx30 proportional gain, Ixx32 velocity feedforward, or Ixx69 output limit.