Posted 19 Dec 2014 I have a 2 axis control that runs a pair of identical servo drives. as of late I have been getting reports from the operators that the two motors, while jogging forward will suddenly run in the reverse direction at a high rate of speed. There is not a reversing function on these axes in an way. I am suspecting there may be a problem in the analog output of the module causing an inversion of the signal which in turn causes the motors to run in reverse. This setup has been in operation without any instance of this happening for around 5yrs before any issue with out of control runs. All cabling has been checked and is properly shielded and grounded. Share this post Link to post Share on other sites
Posted 19 Dec 2014 The symptom suggests a sudden change in the feedback position of the axis indicating that the axis is way ahead of where it should be. The cause could be the encoder or the module. One would expect that to cause a position error. If the axis config for what action to take on position error is "stop motion", that will cancel the jog, but leave the axis enabled and therefore it will continue to attempt to bring actual position in line with command posiiton. Share this post Link to post Share on other sites