Impulsive differential instruction can be used to test the rising and falling edge of the input pulse, when conditions are met, a narrow pulse signal output. PLS, PLF two instructions.
1 PLS instructions
PLS order known as the rising edge of impulsive differential instruction. Its functions are: when a rising edge of the input pulse signal is detected, so the coil element y or m a scanning cycle, resulting in a pulse signal output width for a scanning cycle.
The operation of this directive elements for the output relay y m and auxiliary relays, but no special relays.
PLS order used is shown in Figure 2.
2 PLF instructions
PLF pulse instruction directive, also known as falling edge. Its function is when a falling edge of the input pulse signal is detected, so the coil element y or m a scanning cycle, resulting in a pulse signal output width for a scanning cycle.
The operation of this directive elements for the output relay y m and auxiliary relays, but no special relays.
PLC ONE 