how to use the motor feedback

[金翅大鹏]

I use six servo motor to control them to form some traces.  the motor is from japan ,and every motor has its own encoder , and the endoer output to its servo drive to form closed loop .they say the motor system's closed loop is ve precise ,I do not have to connect the encoder to the motion controller . by the way I use pxi 7354 and umi 7774 to control the motors.  my application is to set the position loop mode to control the six motors'motion correlatively.

 but I want to try to connect the encoder to the motion controller .so the error comes out . first I have to select the step mode in the MAXI  I can start the motor even if I do not connect the feedback,  when I select the serve mode the motor can not work. why ?  the second when the feedback is connected , the motor had to work in a very low velosity ,otherwise the following error will reach the default.even I set the following error is very big , when the velosity come up to some extreme the motor will stop for the following error's limit

who can help me

[Brian_Beal]

Please tell us more about your drive.  What brand and model.  Normally, the encoder is wired to the drive so that the drive can provide commutation and close the current loop.  The drive should have a simulated encoder output that is wired to the controller so that the controller can close the velocity and position loops.  That is how you will be able to use the servo functions of the controller.

[Simon Tew]

Dear Sir/Madam,

I have a similiar problem also. For example, I use Stepper mode with open loop configure in MAX to run a FUJI servo with no problem at all, but once it is configured to close loop in MAX the encoder value doesn't change when monitored from 1D interactive window of MAX. And eventually the following error came out and motor stop!

I have set the correct encoder feedback parameter in Servo drive, and I can read the encoder value by Read Encoder.vi but How come it doesn't show the value in MAX? Is any configuration that I was missed out in MAX? Is need to set the encoder setting in MAX to match the servo encoder output?

Thanks.