Omron CPM1

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CQM1 Cycle Time and I/O Response Time Section 7-1
7-1-3 I/O Response Time
The I/O response time is the time it takes after an input signal has been
received (i.e., after an input bit has turned ON) for the PC to check and pro-
cess the information and to output a control signal (i.e., to output the result of
the processing to an output bit). The I/O response time varies according to the
timing and processing conditions.
The minimum and maximum I/O response times are shown here, using the
following program as an example.
The following conditions are taken as examples for calculating the I/O
response times.
Input ON delay: 8 ms
Overseeing time: 1 ms
Instruction execution time: 14 ms
Output ON delay: 10 ms
Position of output instruction: Beginning of program
Communications ports: Not used.
Note The input ON delay for DC Input Units can be set in the PC Setup.
Minimum I/O Response
Time
The CQM1 responds most quickly when it receives an input signal just prior to
the input refresh phase of the cycle, as shown in the illustration below.
When cyclic output refreshing is used:
Minimum I/O response time = 8 + 15 + 10 = 33 ms
When direct output refreshing is used:
Minimum I/O response time = 8 + 1 + 10 = 19 ms
Maximum I/O Response
Time
The CQM1 takes longest to respond when it receives the input signal just
after the input refresh phase of the cycle, as shown in the illustration below. In
that case, a delay of approximately one cycle will occur.
Input
Output
Input ON delay
With direct output refresh
Instruction execution
Output ON
delay
Cycle time
With cyclic output refresh
I/O refresh
Overseeing, etc.
Output point
Input
point
Input
bit
CPU
processing
Instruction execution
Cycle time
I/O refresh
Overseeing, etc.
Input ON delay
Input
point
Input
bit
CPU
processing
Instruction execution Instruction execution Instruction execution
Output ON
delay
Output point
With direct output refresh With cyclic output refresh