Omron CP1L - 12-2007, Operation Manual

Page: 116 / 673

83
Computing the Cycle Time
Section 2-7
2-7-7 I/O Response Time
The I/O response time is the time it takes from when an input turns ON, the
data is recognized by the CPU Unit, and the user program is executed, up to
the time for the result to be output to an output terminal. The length of the I/O
response time depends on the following conditions.
• Timing of Input Bit turning ON.
• Cycle time.
Minimum I/O
Response Time
The I/O response time is shortest when data is retrieved immediately before I/
O refresh of the CPU Unit. The minimum I/O response time is calculated as
follows:
Minimum I/O response time = Input ON delay + Cycle time + Output ON delay
Note The input and output ON delays depend on the type of terminals used on the
CPU Unit or the model number of the Unit being used.
Maximum I/O Response
Time The I/O response time is longest when data is retrieved immediately after I/O
refresh period of the CPU Unit. The maximum I/O response time is calculated
as follows:
Maximum I/O response time = Input ON delay + (Cycle time
×
2) + Output ON
delay
Input
I/O refresh
Input ON delay
Output ON delay
Cycle time Cycle time
(Interrupt to
CPU Unit)
Output
Minimum I/O
response time
Instruction
execution Instruction
execution Instruction
execution
Input
I/O refresh
Input ON delay
Output ON delay
Cycle time
Cycle time
(Interrupt to
CPU Unit)
Output
Maximum I/O
response time
Instruction
execution Instruction
execution Instruction
execution