Powerflex 755 error autotune

janasamara · May 19, 2017

Hi all, I am trying to configure powerflex 755 to work a close loop but I´m have trouble with autotune rotine. When I choose the rotate tune , the test starts normally and performs the static test successfully. Then when it is going to realize the movement of the axis occurs the following error: number 79( Excessive Load).
If I try to work without performing this test another error appears: error number 7 (motor overload) .
I am using an incremental encoder to do the feedback.
Can anyone help me?
Thank you

janasamara · May 19, 2017

Hi all, I am trying to configure powerflex 755 to work a close loop but I´m have trouble with autotune rotine. When I choose the rotate tune , the test starts normally and performs the static test successfully. Then when it is going to realize the movement of the axis occurs the following error: number 79( Excessive Load).
If I try to work without performing this test another error appears: error number 7 (motor overload) .
I tried to find in the rockwell manual some information on why this error occurred but I did not succeed.
I am using an incremental encoder to do the feedback.
Can anyone help me?
Thank you

Gene Bond · May 19, 2017

Are you disconnecting the load from the motor? Most manufacturer's rotating autotune routines require the motor to be free for the initial tune. Later, ther might be some inertia tune routine, but the 1st rotating test is usually a free-spinning motor.

janasamara · May 19, 2017

Yes, the motor does not have a coupled load.

mdim · May 19, 2017

Did you check directions of motor and encoder? if they don't match you can have problem. Also is there any brake on the motor.
Encoder settings, PPR etc, are they correct?

janasamara · May 19, 2017

When I perform the steering test the message: The feedback polarity does not match the engine speed. How do you want to correct this? I choose automatic . But is this the problem then? I have already re-engineered the encoder, but it still makes the same mistake.
How can I resolve this? The encoder card I am using is the 20-750-ENC-1
In relation to the motor, it is a three-phase motor with brake. The brake is connected to the relay (R0nc) and configured in parameter 935 with bit 16 energized (value 1)

mdim · May 19, 2017

I am not quite sure what means "re-engineering the encoder". Automatic correction changes P.1 bit 5 of the 20-750-ENC-1. So if you changed something you change again the state of the bit.

I would also check if the brake really opens. What is the relay that you use?

janasamara · May 19, 2017

I have an I / O card (20-750-2262c-2r) installed on the powerflex 755 and use the relay output of this card. This relay output is configured by P935.
I have already checked that the brake is correctly energized and it is okay.
I did a test with no encoder, and motor runs well.
I have some doubts about encoder connections. Do you have some diagrams showing how it must be connected?

dmargineau · May 19, 2017

janasamara said:
I have an I / O card (20-750-2262c-2r) installed on the powerflex 755 and use the relay output of this card. This relay output is configured by P935.
I have already checked that the brake is correctly energized and it is okay.
I did a test with no encoder, and motor runs well.
I have some doubts about encoder connections. Do you have some diagrams showing how it must be connected?

See attachment.

mdim · May 19, 2017

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/750-in001_-en-p.pdf

20-750-ENC-1 starts on pg.273. Of course it will depend on what is the encoder type? Can you specify it?

EDIT: dmargineau was faster

Helliana · May 19, 2017

janasamara said:
When I perform the steering test the message: The feedback polarity does not match the engine speed. How do you want to correct this? I choose automatic . But is this the problem then? I have already re-engineered the encoder, but it still makes the same mistake.
How can I resolve this? The encoder card I am using is the 20-750-ENC-1
In relation to the motor, it is a three-phase motor with brake. The brake is connected to the relay (R0nc) and configured in parameter 935 with bit 16 energized (value 1)

To change the polarity of an encoder, you need to swap A and A-. A Powerflex 755 can change it automatically for you, which is the question it asks you. I select automatic and direction test again and it should be happy. I have had older versions firmware get into a loop and always asked you if you want to do the automatic change. If this happens, I swap A and A-, do the direction test again, and see if the drive is then happy.

janasamara · May 19, 2017

Thank you for help me.
It is a incremental quadratura encoder .
manufacturer: SEW
Model: ES7C.

Helliana · May 19, 2017

Also, make sure the motor data exactly matches the name plate data on the motor. If the data does not match, autotune can have issues.

mdim · May 19, 2017

WHat is your supply to the encoder. As per specification, ES7C could be from 4.75 to 30VDC. So it decides based on the supply if it will work as TTL or HTL. So I assume at 5 VDC it will work as TTL and 12-24 it will be HTL, which I hope is like the line driver that AB uses. At what voltage are you? Also distance matters.

janasamara · May 19, 2017

Helliana , thank you for answering me.
I've already done the test several times but the same error always occurs. (Error number 79) .
The motor data exactly matches the name plate data on the motor.

Powerflex 755 error autotune

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