Posted 8 Mar 2022 I have an old Panelview 800 in a system that consists of the PV, a Micro 850 and 10 Powerflex VFd's running conveyor motors. My problems started when one of the motors would not run. It seemed that the PLC was not sending the Run command or the Speed. The problem got worse as I was working on it when two others did the same thing. The current situation is that 8 of the VFD's are getting a Run command and 2 are getting a flickering command. All 10 are getting a 0.0Hz speed command. I connected to the equipment with my laptop and looked at the PLC program and the PV program. I found that in the PV program that all of the user input data, which consists of Motor Speed (Hz), Accel and Decel times and some other timer values for the timing of some conveyor starts and stops, where all gone, set at '0'. this equipment is several years old and predates my presence here. The PLC program seems to be running and passing the commands that it receives to the VFD's. The data is passed to the PLC via Global Variables. I've never encountered this particular problem before. Any ideas? Share this post Link to post Share on other sites
Posted 9 Mar 2022 the micro 850 using CCW assigns initialvalues for most variables and I suspect yours are zero. Make sure there set and then download them. Share this post Link to post Share on other sites
Posted 9 Mar 2022 Thank you for the response! This condition appeared before I connected to it with CCW. I will look at this, but it appears to have lost the settings/data spontaneously? If I put the setting back in from the PV it appears to stay, at least in the short term. They turn off the panel for the weekend and I was concerned that there was something going on with it due to that. Share this post Link to post Share on other sites
Posted 9 Mar 2022 I'm not overly familiar with PV800 but my first thought is that if the problem is related to cycling the power, is there a PV powerup (or other) macro running that sets your initial values to zero? Assuming the 800 has powerup macros available, a problem with this theory is that you said the problem progressed through drives, rather than simultaneously affecting them all on powerup. Just spit balling here... Share this post Link to post Share on other sites
Posted 1 Apr 2022 Divide and conquer. First find out if the plc is sending a reference that makes it to the drive. Since all 10 are 0, my gut is the plc, not the drives Share this post Link to post Share on other sites
