Stepper controller velocity change

[cch1955]

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.

[support]

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.

[cch1955]

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

[support]

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.