Timer :- Timer is nothing but a specialized clock in a programming software used to count the preset time intervals. In Siemens PLC we have various ty pes of timers as :- 1) S_PULSE(Pulse timer), 2) S_PEXT(Extended Pulse Timer), 3) S_ODT(On Delay Timer), 4) S_ODTS(Retentive On Delay Timer), 5) S_OFFDT(Off Delay Timer). You must find out another five instruction sets in Timer Block in Simatic Manager STEP 7 as :- -(SP) pulse timer coil, -(SE) extended pulse timer coil, -(SD) on delay timer coil, -(SS) retentive on delay timer coil, -(SF) off delay timer coil. 1) S_PULSE(Pulse timer) :- S_PULSE Timer Above Fig Shows how to use this timer in programming software,in this fig i have used 5 sec as a preset value, If you want to change it replace the 5 with any duration you want in S5T# 5 S. In S_PULSE timer if input to timer is ON then timer starts Counting time as well as we get the Output at the instant the input is made ON. In t...