Rockwell Automation 1746-HSTP1 Stepper Controller Module/ User Manual - Manual (Page 33)

Publication 999-121 - December 1999
4-2 Module Operation
Command
The Command mode directs all stepper motor operations, through the
Stepper Translator. There are translators which require a pulse train
and direction to operate. Other translators require a CW (positive
direction) pulse train and a CCW (negative direction) pulse train. The
CW and CCW designations refer to directions of stepper motor
rotation. The Stepper Controller can be configured for either type of
translator.
When operating in either the Configuration or the Command mode,
Module status is reported to the SLC Controller.
Operation Using the Pulse and Direction Outputs
If the Stepper Translator requires pulse and direction outputs,
configuration output word 0, bit 10 has to be set to a logic “1”, since
the default state of the Stepper Controller is set up for CW and CCW
pulses (logic “0”, on bit 10). Assuming the Module is inserted in slot 0,
the bit address is 0:0.0/10.
The pulse train and direction signal are illustrated just below the
unconditional rung for clarity. The programmed speed value controls
the frequency of the pulse train and the sign of the destination value
controls the direction output of the Stepper Controller. An alternate
configuration method is to ensure bit 10 of word 0 is true when
moving or copying a data file to word 0 of the output address.
Figure 4.1 Pulse and Direction Outputs
Fixed Speed Operation
Operation at fixed speed will cause the pulse and direction to
accelerate at the programmed acceleration rate and reach the final
Pulse
Direction
CW/Plus Direction CCW/Minus Direction