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General => Technical support => Topic started by: cch1955 on July 31, 2006, 02:41:41 PM

Title: Stepper controller velocity change
Post by: cch1955 on July 31, 2006, 02:41:41 PM

If I issue a STEPMOVE comand can I midway trough the move change the velocity by issuing a SETSTEP command with a new velocity?

I have an application that is on a winder with a stepper driven laying axis where I need to follow the supply spool and allow for operator induced speed changes out of the PLC control loop.

Title: Re:Stepper controller velocity change
Post by: support on July 31, 2006, 03:48:36 PM

Yes, it is possible to issue a STEPSPEED command to change the speed while the stepper motor is already moving at constant speed. i.e. you can't change speed during acceleration/decceleration phase.

Also stepspeed change the speed without acceleration/deceleration so if the changes is abrupt then you need to change the speed in stages so as not to cause the motor to miss some steps.

Title: Re:Stepper controller velocity change
Post by: cch1955 on July 31, 2006, 04:07:34 PM

This makes my task much more simple. :)

I am mixed up some: I think you want to make sure I also include accel-decel parameter in change STEPSPEED command to make sure speed change is smooth.

If  I not include Decel-Accel parameter in SETSPEED it will be abrupt speed change and could loose motor control.

Is my understnading correct?

Thanks

Title: Re:Stepper controller velocity change
Post by: support on July 31, 2006, 08:31:50 PM

No. When you do a Stepspeed in the middle of a move, it just change to the new speed immediately. The acc/dcc parameters are ignored. So you have to change speed in stages if the change is very abrupt.