text: <s>[INST] Power Flex 700 started running in reverse Hello, I have a 700 Power flex with vector control that was running correctly. Power was dropped to the unit during clean up. When it was brought back online the motor ran in reverse. We checked the settings and it was still in Unipolar in Direction mode. I had to change the Direction mode to Reverse Dis to get the motor running the correct direction. Checking the other parameters from our setup sheet everything was correct. Does anyone have an idea what may have caused this malfunction to happen? Could it be that drive is starting to fail? I haven't checked to see if there is a battery backup for the memory. [/INST] The most likely thing is that somebody pressed the (<- ->) direction change button on the HIM module inadvertently. I've done it. I think you are referring to Parameter 190, the Direction Mode. This has options of Unipolar, Bipolar, and Reverse Disable. The Unipolar selection means that the analog or network reference polarity will not change the direction of the drive, but that the drive logic can. Drive logic includes discrete inputs configured for direction command, or bits in a network command, or the direction button on the HIM module. When I have an application that goes in only one direction like a pump or conveyor, I always select Reverse Disable on the Direction Mode. To just prevent the HIM module from making such a change, you can mask it out with the Direction Mask parameter. At the time of the undesired operation, you might have been able to determine what input was commanding the reverse direction by reading the value of the Direction Owner parameter (parameter 291). I don't think that will show anything useful now that you have disabled reverse. \\n </s>