kachow12345
Member
Hi,
I'm new to PLCs and learning about PLC Scan times for Schneider PLCs
I've derived the PLC scan time using the free running blocks. The PLC Scan time of the simulation is 25ms
I've generated a 1 second pulse with a pulse counter using two TON blocks (500ms each TON) and a pulse trigger that is reset after each second.
I've run the program for 60 seconds and recorded the number of pulse counts.
I was expecting to see 60 counts (i.e 1 second pulse = 1 count, so for 60 seconds you get 60 pulses), however, I've recorded 57 counts.
Can someone please explain to me the theory behind what is happening and why my TON 1 second pulse counter is delayed by 3 seconds (3 pulses).
I'm new to PLCs and learning about PLC Scan times for Schneider PLCs
I've derived the PLC scan time using the free running blocks. The PLC Scan time of the simulation is 25ms
I've generated a 1 second pulse with a pulse counter using two TON blocks (500ms each TON) and a pulse trigger that is reset after each second.
I've run the program for 60 seconds and recorded the number of pulse counts.
I was expecting to see 60 counts (i.e 1 second pulse = 1 count, so for 60 seconds you get 60 pulses), however, I've recorded 57 counts.
Can someone please explain to me the theory behind what is happening and why my TON 1 second pulse counter is delayed by 3 seconds (3 pulses).