Input Refresh
Input Terminals
Input Device
Output Device
Ladder Processing
Output Refresh
Other Processing
Output Terminals
Input CircuitOutput Circuit
I0: ON
I1: OFF
I2: ON
Q0: ON
Q1: OFF
Q2: ON
0: ON
1: OFF
2: ON
0: ON
1: OFF
2: ON
Repeat operations
One sequence of operations is set as one
scan, and the time required is set as the
scan time.
The output devices are updated
according to the ladder program.
The input device values are applied to the
ladder program.
Processing other than the ladder
processing is called the END
processing.
The ON/OFF status of the input terminal
(external input) is applied to the input
circuit. The input refresh loads the external
input status into the input devices (I) by
way of the input circuit.
A delay occurs until the ON/OFF status of
the input circuit is applied to the input
devices (I). The delay time is equal to filter
time + 1 scan time.
The output refresh applies the status of the
output devices (Q) to the output circuit, and
then the ON/OFF status of the output
terminals (external input) is updated.
A delay occurs until the values of the output
devices (Q) are applied to the output circuit.
The delay time is at maximum 1 scan time.