Determining The Cycle Time - Siemens LOGO! Manual

Determining the cycle time

The program cycle is the complete execution of the circuit program, that is, primarily the
reading in of the inputs, the processing of the circuit program and the subsequent reading
out of the outputs. The cycle time is the time required to execute a circuit program once in
full.
The time required for a program cycle can be determined using a short test program. This
test program is created in LOGO! and returns a value during its execution in parameter
assignment mode from which the current cycle time is derived.
Test program
1. Create the test program by linking an output to a threshold trigger and connecting the
trigger input with an inverted flag.
2. Configure the threshold trigger as shown below. A pulse is generated in each program
cycle due to the inverted flag. The trigger interval is set to 2 seconds.
3. Now start the circuit program and switch LOGO! to parameter assignment mode. In this
mode, view the trigger parameters.
4. The reciprocal value of f
program in its memory.
1/f
a
LOGO!
Manual, 10/2017, A5E01248535-AA
a
= cycle time in s
is equivalent to the LOGO! execution time of the current circuit
B
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