I/O Response Time - Omron C200H Operation Manual

I/O Response Time

6-4 I/O Response Time
Minimum I/O Response
Time
Cycle
Input
signal
Input
ON delay
Output
signal
234
The I/O response time is the time it takes for the PC to output a control signal
after it has received an input signal. The time it takes to respond depends on
the cycle time and when the CPU receives the input signal relative to the in-
put refresh period. The I/O response times for a PC not in a Link System are
discussed below. For response times for PCs with Link Systems, refer to the
relevant System Manual.
The minimum and maximum I/O response time calculations described below
are for where 00000 is the input bit that receives the signal and 00200 is the
output bit corresponding to the desired output point.
00000
The PC responds most quickly when it receives an input signal just prior to
the I/O refresh period in the cycle. Once the input bit corresponding to the
signal has been turned ON, the program will have to be executed once to
turn ON the output bit for the desired output signal and then the I/O refresh
operation would have to be repeated to refresh the output bit. The I/O re-
sponse time in this case is thus found by adding the input ON-delay time, the
cycle time, and the output ON-delay time. This situation is illustrated below.
Cycle time
Instruction
execution
I/O refresh
CPU reads
input signal
I/O response time
Minimum I/O response time = input ON delay + cycle time + I/O refresh time
+ output ON delay
00200
Cycle time
Instruction Instruction
execution execution
Output ON delay
Section 6-4