8-2
Section
CPM2A/CPM2C Cycle Time and I/O Response Time
525
Minimum I/O Response Time
The CPM2A/CPM2C responds most quickly when it receives an input signal just
prior to I/O refreshing, as shown in the illustration below.
Input ON delay (10 ms)
I/O refreshing
Input
point
Input
bit
Output
point
I/O refreshing
Program execution and other processes
(15 ms)
Min. I/O response time = 10+15+15 = 40 ms
Output ON delay (10 ms)
Maximum I/O Response Time
The CPM2A/CPM2C 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 ON delay (10 ms)
I/O refreshing
Input
point
Input
bit
Output
point
Program execution
and other processes
(15 ms)
Max. I/O response time = 10+15
×
2+15 = 55 ms
Output ON delay (10 ms)
I/O refreshing
Program execution
and other processes
(15 ms)
I/O refreshing
8-2-3 One-to-one PC Link I/O Response Time
When two CPM2A/CPM2Cs are linked 1:1, the I/O response time is the time re-
quired for an input executed at one of the CPM2A/CPM2Cs to be output to the
other CPM2A/CPM2C by means of 1:1 PC Link communications.
The minimum and maximum I/O response times are shown here, using as an
example the following instructions executed at the master and the slave. In this
example, communications proceed from the master to the slave.
Input
Output (LR)
Input
(LR)
Output
Master
Slave
The following conditions are taken as examples for calculating the I/O response
times. In CPM2A/CPM2C PCs, LR area words LR 00 to LR 15 are used in 1:1
data links and the transmission time is fixed at 21 ms.
Input ON delay:
10 ms (input time constant: default setting)
Master cycle time:
10 ms
Slave cycle time:
15 ms
Output ON delay:
15 ms
Minimum I/O Response Time
The CPM2A/CPM2C responds most quickly under the following circumstances:
