MicroLogix PTO Instruction

The PWM function is only available when using the BXB models of the MicroLogix 1200 or 1500
Locate the Function Files under Controller in RSLOGIX 500 v4.00 or later and select
the PTO tab, then select the [ + ] next to PTO:0 ( See Below )

Enter the following parameters as the "Minimum Configuration" required for the PTO to generate pulses.

PTO:0.OUT Select Destination Output for pulses : Output O:0/2 or O:0/3

PTO:0.OF Output Frequency - Frequency of pulses : 0 to 20,000 Hz
Data less then zero and greater then 20,000 generates a
PTO error

PTO:0.TOP Total Output Pulses - Determines total number of pulses
to be generated by the controller

PTO:0.ADP Accel/Decel Pulses - How many of the total pulses will
be used for the Accel/Decel component

The following example will generate 10,000 pulses on Output O:0/2
at a frequency of 500Hz and 100 pulses will be used for Accelerating
and 100 pulses will be used for Decelerating.

The following ladder logic will need to be entered into File #2

By toggling Bit B3/0 the PTO can be activated. Once running the PTO will generate the number of pulses entered into the PTO:0.TOP word and then stop. To restart, toggle B3/0.

General information on the PTO
Once running the PTO will continue to generate pulses until all pulses have been generated or the PTO:0/EH ( Enable Hard Stop ) bit has been activated.
Once the EH bit is set the instruction will generate a PTO error of 1 (hard stop detected).
In order to clear this error the PTO instruction must be scanned on a false rung of logic, and the EH bit must be off.
To change the Total Output Pulses Generated in a working program a new value can bemoved into PTO:0.TOP by using the MOV command.