I/O Response Time - Omron SYSMAC C2000H Operation Manual

I/O Response Time

6-4

I/O Response Time

00000
Minimum I/O Response
Time
Maximum I/O Response
Time
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.
00200
The PC responds most quickly when it receives an input signal just prior to
the input 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 input refresh
and overseeing operations would have to be repeated before the output re-
fresh operation refreshes the output bit. The I/O response time in this case is
thus found by adding the input ON-delay time, the cycle time (including the
I/O refresh times and the overseeing time), and the output ON-delay time.
This situation is illustrated below.
CPU reads
input signal
Cycle time
Cycle
Input refresh
Input
signal
Input ON delay
Output
signal
I/O response time
Minimum I/O response time = input ON delay + cycle time + I/O refresh time
+ overseeing time + output ON delay
The PC takes longest to respond when it receives the input signal just after
the input refresh phase of the cycle. In this case the CPU does not recognize
the input signal until the end of the next cycle. The maximum response time
is thus one cycle longer than the minimum I/O response time, except that the
input refresh time would not need to be added in because the input comes
just after it rather than before it.
Address Instruction
00000 LD
00001 OUT
Overseeing
Cycle time
Output refresh
CPU writes
output signal
Output ON delay
Section 6-4
Operands
00000
00200
241