Power Flex 525 Not Stopping

[nmk34]

I have this 525 that i am controlling it via ethernet. I needed to jog the drive using a start PB. when the button is pressed, the drive moves and when you let go of the button it stops. it works fine, but I noticed some times when the button is released the drive continues to run even though the drive output VFD#:O.Start is off. i made a workaround that says when jogging and button is released this will trigger VFD#:O.Stop. and that works. There got to be another way to do this?

 

[BachPhi]

Yes, If no Fwd & no Rev then do Stop.

 

[Ken Roach]

Usually the problem is the other way around; the occasional timing interaction between logic and the EtherNet/IP RPI timeout causes both a Start =1 and Stop = 1 bit to be sent to the drive when you intend it to Start, but the Stop bit overrides the Start bit. This is usually described by the user as "the drive sometimes fails to start on command".

Examine your logic carefully. How long is the STOP bit held true ?

What I do is keep the STOP bit true until I get feedback in the Input word that the drive has stopped running.

 

[kamenges]

There is no two wire control equivalent on Ethernet/IP for the 525. If you start the drive using .Start you need to stop the drive using .Stop.
If you want to have the drive start and stop with a single bit you will need to use the actual .Jog bit in the command word.

[/b]Ken Roach[/b] is correct about start/stop bit timing. Stop always wins. I am much more open loop than Ken with my stop commands to the drive. I control an off delay timer from the .Start bit and then issue a .Stop based on the timer timing bit (.tt) from that timer. Since the 525 needs to see a leading edge of the .Start AFTER the .Stop is released this has worked pretty solidly for me.

Keith

 

[BachPhi]

My approach do not use a direct PB to Start! But rather Fwd/Rev to Start along with active monitor TMR.

 

[01101]

Since the 525 needs to see a leading edge of the .Start AFTER the .Stop is released this has worked pretty solidly for me.

Keith

Same, I have been using a seal-in branch on mine to check the status word, holding the stop signal on until the drive active status goes off then release the stop signal.

 

[robertmee]

There is no two wire control equivalent on Ethernet/IP for the 525. If you start the drive using .Start you need to stop the drive using .Stop.
If you want to have the drive start and stop with a single bit you will need to use the actual .Jog bit in the command word.

[/b]Ken Roach[/b] is correct about start/stop bit timing. Stop always wins. I am much more open loop than Ken with my stop commands to the drive. I control an off delay timer from the .Start bit and then issue a .Stop based on the timer timing bit (.tt) from that timer. Since the 525 needs to see a leading edge of the .Start AFTER the .Stop is released this has worked pretty solidly for me.

Keith

I pretty much do as Ken does. Loss of Start Latches stop until its stopped, then stop releases. For the start, I have a timer that says drive must be stopped for x time before the next start is issued. Drive Started latches around this timer Dn. That's worked flawlessly for 15 years. I added the timer for start as there was a rare occasion of re-issuing a start on the same scan as the stop expiring in code...IE an operator hammering a jog button. That would also cause the behavior of the drive not restarting even though the stop had been released.