raghudt Posted January 23, 2013 Share Posted January 23, 2013 Hi Thanks for looking at this. I have been using a PMAC Mini (ISA) for performing 2 axis of servo motion. Axis 1 was used for Torque Control; Axis 2 was used for Position (Velocity) Control. It has worked ok for many years. Last week, I could not get it to Jog properly on Axis 2. Using PEWin software, if I issue a Jog Stop ( J/ ) command, the motor is energized and immediately starts moving at a slow rate in one direction. Attempts to change the direction using the J+ or J- command has no effect. Also Jog to Position command ( J:xxxx) does not work. I measured the Servo Voltage output from the PMAC Mini card. It was around 150mV before energizing; and sligtly more positive (155 mV) when the J/ command was issued. No change at all when a J:1000 command is issued. Is this a problem with some variables becoming corrupt? Or is the PMAC card dead? Thanks for any help! Link to comment Share on other sites More sharing options...
tecnico Posted February 14, 2013 Share Posted February 14, 2013 I would check the value of the output register of the DAC (m102 in the suggested variables), the encoder feedback (does the PMAC see the motor moving?) If encoder feedback is working and the DAC register is giving some output you should see the output voltage reflect the DAC value (32000 should be about 10 volts). Another factor could be i269, that sets the maximum DAC value allowed. Note: all these tests shoud be carried out following the safety rules Link to comment Share on other sites More sharing options...
Richard Naddaf Posted February 14, 2013 Share Posted February 14, 2013 Could you jog axis #1? You can troubleshoot using the following steps: - Kill all motors (issue CTRL^K) - Disconnect Drive power for safety - Disconnect the drive from the PMAC (pull out the motor connector) - Move motor #2 by hand (if possible). Do you see encoder feedback in the position window? Y or N? - Open motor #2 status window in the PeWin - Issue #2O50 (positive open loop command of 50%) - Is the Amplifier Enable bit highlighted in the motor status window? Y or N? - Is the measured voltage output positive half of what the maximum specified in I269 (scaled to 10V)? Y or N - Issue #2O-50 (negative open loop command of 50%) - Is the measured voltage output negative half of what the maximum specified in I269 (scaled to 10V)? Y or N - Kill motor after test (issue #2K or CTRL^K) If all your answers are YES, then the PMAC is in good shape. Otherwise, share motor status window display and measured voltage values. Link to comment Share on other sites More sharing options...
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