Mode Of Operation Pulsegen - Siemens SIMATIC S7-1200 Function Manual

9.4.3.2

Mode of operation PULSEGEN

Impulse width modulation
The duration of a pulse per period duration is proportional to the input variable. The cycle
assigned via PER_TM is not identical to the processing cycle of the PULSEGEN instruction.
Rather, a PER_TM cycle is made up of several processing cycles of the PULSEGEN
instruction, whereby the number of PULSEGEN calls per PER_TM cycle determines the
accuracy of the pulse width.
An input variable of 30% and 10 PULSEGEN calls per PER_TM mean the following:
● "One" at the QPOS_P output for the first three calls of PULSEGEN (30% of 10 calls)
● "Zero" at the QPOS_P output for seven further calls of PULSEGEN (70% of 10 calls)
PID control
Function Manual, 03/2017, A5E35300227-AC
Instructions
9.4 PID basic functions
461