# Powerflex 70 Reverse Direction



## rlvmaiden (Nov 3, 2020)

Would it just be a matter of running another PLC output contactor to Digital In 3, and then setting that Parameter (363) to value 9 (Run Reverse)? Then I would verify that Digital In 1 Parameter (361) is set to value 8 (Run Forward) so that it continues to operate properly when a normal run command is set, as I'll likely need to change Parameter 190 to bipolar to allow the VFD to run in reverse, or is this even necessary?


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## gpop (May 14, 2018)

The drive is using a 20-com-r remote i/o card so simply program it to do what you want it to do.

It says its a 1/4 rack but as its connected to a slc 5 its probably a 1/2 rack. Second word will be the run/stop commands just look in the manual and add the reverse command. Also add a time delay as rapidly switching especially if you are not using decel to stop will cause problems. 

the command to reverse could be a switch to the plc or you could get fancy and automate it.


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## just the cowboy (Sep 4, 2013)

rlvmaiden said:


> Would it just be a matter of running another PLC output contactor to Digital In 3, and then setting that Parameter (363) to value 9 (Run Reverse)? Then I would verify that Digital In 1 Parameter (361) is set to value 8 (Run Forward) so that it continues to operate properly when a normal run command is set, as I'll likely need to change Parameter 190 to bipolar to allow the VFD to run in reverse, or is this even necessary?


Basically yes if DI#1 is run forward do like you said and make DI#3 run reverse. As @gpop said I don't know if that drive has anti plugging, if not you have to do the time delay/zero motion route. I would also only allow it to run reverse in jog mode for clearing jams.


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## rlvmaiden (Nov 3, 2020)

just the cowboy said:


> Basically yes if DI#1 is run forward do like you said and make DI#3 run reverse. As @gpop said I don't know if that drive has anti plugging, if not you have to do the time delay/zero motion route. I would also only allow it to run reverse in jog mode for clearing jams.


The reverse command I'm adding will only be for a quick jog when it's jammed, it'll never be running from forward straight to reverse. Do I need to change parameter 190 to bipolar or can I leave it Unipolar and just program DI3 for reverse run? Will this work or does 190 need to be Bipolar for the VFD to send reverse commands?


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## gpop (May 14, 2018)

rlvmaiden said:


> The reverse command I'm adding will only be for a quick jog when it's jammed, it'll never be running from forward straight to reverse. Do I need to change parameter 190 to bipolar or can I leave it Unipolar and just program DI3 for reverse run? Will this work or does 190 need to be Bipolar for the VFD to send reverse commands?



has to be bipolar.

Seems weird that you want to use both remote i/o and digital inputs as this can cause problems (remote i/o owns the stop command)


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## rlvmaiden (Nov 3, 2020)

gpop said:


> has to be bipolar.
> 
> Seems weird that you want to use both remote i/o and digital inputs as this can cause problems (remote i/o owns the stop command)


Take the drawing with a grain of salt, I can't remember if that remote I/O is actually there or not, it wouldn't be the first time the drawings for this old plant were wrong. I do know for a fact, though, that the PLC sends a start command from its output card, so if it's working in that configuration then it should be a quick thing to run one more wire from the terminal strip to this VFD and change a couple of parameters.

Thanks for all your help guys.


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## just the cowboy (Sep 4, 2013)

We do our start/stop and speed control hardwired now. We do our feedback IP or Remote rack. This way if PLC dies drive is shutting down. 
We just had our first case of a IP controlled drive ( non AB ) starting when a PLC crashed. Drive used a IP/Modbus controller that took a pulse to start, PLC must of sent a pulse when it crashed and started the drive. It sat there and pumped 900,000 gals of water before it was found Monday morning. Plant was shutdown for maintenance so the PLC that would of received the communication fail alarm was off line.


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## rlvmaiden (Nov 3, 2020)

just the cowboy said:


> Basically yes if DI#1 is run forward do like you said and make DI#3 run reverse. As @gpop said I don't know if that drive has anti plugging, if not you have to do the time delay/zero motion route. I would also only allow it to run reverse in jog mode for clearing jams.


So DI#1 and DI#2 parameters are set to 1 (enable) which runs the drive and coasts to stop when it drops out. I tried changing the parameter to 8 (run forward) but the drive wouldn't start. Apart from DI 1/2, the other parameters are set to 0 (unused). If I try to set them to anything else (run fwd, run reverse) the drive will not start. There seems to be a conflict in the drive when it's being ran with Enable and theres fwd/rev commands programmed in its DIs, even if they're not seeing any signals.

Any ideas on how to get this thing to run in reverse?


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## rlvmaiden (Nov 3, 2020)

rlvmaiden said:


> So DI#1 and DI#2 parameters are set to 1 (enable) which runs the drive and coasts to stop when it drops out. I tried changing the parameter to 8 (run forward) but the drive wouldn't start. Apart from DI 1/2, the other parameters are set to 0 (unused). If I try to set them to anything else (run fwd, run reverse) the drive will not start. There seems to be a conflict in the drive when it's being ran with Enable and theres fwd/rev commands programmed in its DIs, even if they're not seeing any signals.
> 
> Any ideas on how to get this thing to run in reverse?
> [/QUOTE


Problem solved, found the word in the remote IO that controls direction. Should've just went that route from the beginning.


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## just the cowboy (Sep 4, 2013)

Looks like 190 should be unipolar.
Unipolar = both directions controlled by logic
Bi polar = speed command goes - To + example -10 to +10 volt speed input.
So start there.
What setting are in D1 and D2 Defaults are D1 stop
d2 start that don't match your print.
Try this
Set D1 to 5
D2 to 1
D3 to 6
Apply voltage to D1 and D2 enable and run.
if it runs apply voltage to D3 Then D1 and D2 Does it run the other way.


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## gpop (May 14, 2018)

rlvmaiden said:


> Problem solved, found the word in the remote IO that controls direction. Should've just went that route from the beginning.



if you went to diagnostics on the drive you would probably have found that the remote i/o was over writing the digital input on every scan (digital says 1 remote says 0 thousands of times a second). You might have been able to look at direction owners where it may have shown both were active then disabled the remote i/o using a mask but that's to much like hard work when you can just use remote i/o to fix the problem. 

Glad you got it fixed. 

p.s they no longer sell the 20-com-r-4 cards so you may want to consider planning how you will deal with a bad card should it happen in the future.


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