I/O Response Time - Omron CPM1 Programming Manual

Process
1. Overseeing
2. Program execution
3. Cycle time calculation
4. I/O refresh
5. Peripheral port servicing
Cycle time

8-1-3 I/O Response Time

Minimum I/O Response Time The CPM1/CPM1A responds most quickly when it receives an input signal just
Input
point
Input ON delay (8 ms)
Input
bit
Output
point
The average processing time for a single instruction in the user's program is as-
sumed to be 2.86 µs. The cycle times are as shown in the following table.
Calculation method
Fixed
2.86 × 500 (µs)
Negligible
0.01 × 1 + 0.005 × 1 (µs)
Minimum time
(1) + (2) + (3) + (4) + (5)
Note 1. The cycle time can be read from the PC via a Programming Device.
2. The maximum and current cycle time are stored in AR 14 and AR 15.
3. The cycle time can vary with actual operating conditions and will not neces-
sarily agree precisely with the calculated value.
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 process the in-
formation and to output a control signal (i.e., to output the result of the proces-
sing 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 fol-
lowing program as an example.
The following conditions are taken as examples for calculating the I/O response
times.
Input ON delay:
Overseeing time:
Instruction execution time:
Output ON delay:
Peripheral port:
prior to I/O refreshing, as shown in the illustration below.
I/O refreshing Program execution and other processes
Min. I/O response time = 8+15+10 = 33 ms
Time with Programming De-
vice
0.6 ms
1.43 ms
0 ms
0.06 ms
0.26 ms
2.35 ms
Input
8 ms (input time constant: default setting)
1 ms (includes I/O refresh for CPM1A)
14 ms
10 ms
Not used.
(15 ms)
Output ON delay (10 ms)
Section
Time without Programming
Device
0.6 ms
1.43 ms
0 ms
0.06 ms
0 ms
2.09 ms
Output
I/O refreshing
8-1