Allen Bradley motion control problem

Hi

I am using the 2-Axis motion control module of Allen Bradley model M02AE, which is used in a Controllogix chassis.
One of the motors connected to the module failed, so we replaced it with a motor of the same make and type. When we run the new motor, we always get a position error. That is, the motor moves but the actual position does not match the commanded position. We tried replacing the motor with a one that has been tested before on the same module, but we get the same error. Is there any way we can make the actual position follow the commanded position? I tried tuning, but it down not work.

How did the first motor fail?

Have you ruled out a mechanical bind-up?
Otherwise, it sounds like it could be a loose feedback connection.

ettikudiappan said:

One of the motors connected to the module failed

Click to expand...

Define failed.
Caught fire, blew into little pieces or did it (all of a sudden)start showing a position error?

When we run the new motor, we always get a position error. That is, the motor moves but the actual position does not match the commanded position.

Click to expand...

How many revs does it run? I am agreeing with Rick, Are you sure there isn't a mechanical bind, or a bad connection either in the encoder cable or at the TB on the MO2AE. If the motor runs for some time, then gives the position error, try disconnecting the motor from it's load and see if things improve. If the error persists start checking cable connections.

Is there any way we can make the actual position follow the commanded position?

Click to expand...

When using any of the CLGX motion commands, you are telling the actual position to follow the commanded position. That is why it is called 'commanded' position.

Try the hook up test again.

This will verify your connection. It doesn't look like the feed back is working.

Are you using absolute encoders?
Have you reset the home count if so?

Are you using absolute angular encoders?
Have you set the zero position properly if so?

My experiences with other brands in the maintenance field would lead me to where rdrast has suggested--an absolute encoder must be homed in order to "Be" where your command tells it to.

THIS IS A M02AE!!!!

FIRST, IT DOES NOT HAVE AN ABSOLUTE ENCODER INTERFACE!!!!!!!!!

SECOND, ABSOLUTE ENCODERS DO NOT NEED TO BE HOMED.

STOP GUESSING! IT DOESN'T HELP. IT JUST CONFUSES THE CONFUSED.