deltaa Posted June 10, 2013 Share Posted June 10, 2013 System config, == External micro stepping amplifier Two phase stepping motor Geo Brick LV drive channel 4 output Step/Dir signal == Parameters used, == I403=$3504 I404=$3504 I8003=$C78018 I7040=8 == Use jog command #4j+ or #4j- to start motor, motor runs without problem, then #4j/ to stop jogging, after the motor stops, it's still vibrating. Use scope to check the pulse and direction signal from Geo Brick LV, these two signals still have outputs. Anyone has similar experience? What could be wrong? Thanks Link to comment Share on other sites More sharing options...
steve.milici Posted June 10, 2013 Share Posted June 10, 2013 What are your PID gains for the motor? Can you send me you full configuration? Link to comment Share on other sites More sharing options...
deltaa Posted June 10, 2013 Author Share Posted June 10, 2013 The PID gains are I430=4096;Motor 4 PID Proportional Gain I431=0;Motor 4 PID Derivative Gain I432=16384;Motor 4 PID Velocity Feed Forward Gain I433=10000;Motor 4 PID Integral Gain I434=0;Motor 4 PID Integration Mode I435=4096;Motor 4 PID Acceleration Feed Forward Gain I436=0;Motor 4 PID Notch Filter Coefficient N1 I437=0;Motor 4 PID Notch Filter Coefficient N2 I438=0;Motor 4 PID Notch Filter Coefficient D1 I439=0;Motor 4 PID Notch Filter Coefficient D2 Do I need to tune the position loop for an external pulse/direction setup? By the way, when I jog to specified position using #4j=***, the problem does not happen. It only happens when using jog stop command j/ when the motor is moving. Link to comment Share on other sites More sharing options...
steve.milici Posted June 10, 2013 Share Posted June 10, 2013 If PMAC tries to stop at a fractional count this can happen. You should add one count of deadband (I464=-16 and I465=16) for this motor. Note that a J! should always force PMAC to an integer count. Link to comment Share on other sites More sharing options...
steve.milici Posted June 10, 2013 Share Posted June 10, 2013 Also note that you should be using the setup parameters (including PID gains) as specified in the Brick-LV manual for Pulse and Direction setup. See the section titled "Step and Direction PFM Output (To External Stepper Amplifier)" starting on page 49. Link to comment Share on other sites More sharing options...
deltaa Posted June 10, 2013 Author Share Posted June 10, 2013 Thanks Steve, both deadband setting and j! solved the problem. Link to comment Share on other sites More sharing options...
steve.milici Posted June 11, 2013 Share Posted June 11, 2013 One other note using just 1/2 count of deadband should be sufficient (I465=8). Link to comment Share on other sites More sharing options...
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