Omron SYSMAC C Series User Manual page 100

Scan time
Resetting of watchdog timer
@| Checking of user program memory
Checking of I/O bus
E a Execution time and variables
The required scan time differs depending on the configuration of the
system, the number of I/O units, the number of special instructions, and
whether peripheral devices are connected.
The following table shows the time required for each internal operation.
1.07ms (fixed)
to output unit from I/O relays
Reading data input from input unit to 1/0 relays
@| Writing data (result of instruction execution)
1.04ms+0.33msxN
where,
N = 1 when a 28-point I/O unit or I/O link unit is used
or
N = 2 when a 56-point I/O unit is used
@)| Execution of instructions in the user program
Total time for executing instructions. The time required for
execution differs depending on the instruction. (Refer to the
section below, List of instruction execution times.)
Servicing of commands input from peripheral devices such as
programming console, graphic programming console, etc.
1.1ms
The scan time can be obtained by adding 1, 2, 3, and 4 in this table. An
adequately short period of a scan time is important to ensure an efficiently 2a
error-free operation. This is particularly important when using the
high-speed timer, which malfunctions if the scan time exceeds 10ms.