Stepmove question

[cch1955]

What is the minimum speed in steps per second the Fx2424 can use with a Stepmove command?

What speed will the Stepspeed default to if the stepspeed is set lower than the minimum speed?

If a Stepstop is executed during a stemove command, is there any need to clear a buffer that may have a remaining steps from the terminated stepmove -  i.e. like steps left in the move buffer for example which will effect a later stepmove command?

Thank you.

[support]

The minimum speed is 1 step per second. Since this is an integer value you can't set it lower than 1.

If you run STEPSTOP during a STEPMOVE command, the motion is stopped and there is no buffer to clear. The next time you run the STEPMOVE again it will begin from the current location.

It does affect the STEPCOUNT and STEPCOUNTABS value since the move is terminated prematurely.

[cch1955]

I appreciate the information.

I understand the STEPMOVE command computes the velocity profile for a move based on the STEPSPEED command last given before the STEPMOVE comand is encountered.

Once the STEPMOVE is executing and is at full velocity , STEPSPEED can be changed repeatedly during the STEPMOVE. If STEPSPEED is sent after the move has started in either the Accel or decel portions of the move the new STEPSPEED will be ignored.

Will it cause any problems with the move if STEPSPEED is sent during the Accel or Decel portions of the move? If so what are the problems?

Is their a flag somewhere that can be read to indicate a STEPMOVE is in the Accel/Decel portion (0) or is now in the maximum velocity portion (1) of a move?

Thanks

[support]

If you run STEPSPEED during acceleration phase the PLC ignores the change and will continue with the acceleration steps that is already in motion  until it reaches the previously defined maximum PPS and immediately changes to the newly defined maximum PPS. This can be an abrupt change and not recommended.

If you run STEPSPEED during the deceleration it is completely ignored by the PLC.

There is no flag to indicate that the stepper is in the acceleration or deceleration phase. But you can use the STEPCOUNT function to check if the stepper is still in the acceleration phase. i.e IF STEPCOUNT() < acceleration steps it must be still within the acceleration phase.