Omron SYSMAC CS Series Operation Manual page 535

Computing the Cycle Time
1: Overseeing
Checks the I/O bus and user program memory, checks for
battery errors and refreshes the clock.
2: Program Execution
Executes the user program, and calculates the total time
time taken for the instructions to execute the program.
3: Cycle Time Calculation
Waits for the specified cycle time to elapse when a minimum
(fixed) cycle time has been set in the PLC Setup.
Calculates the cycle time.
• Remote I/O for DeviceNet (Master) Units and the number of remote I/O
words
• Use of protocol macros and the largest communications message
• Socket services for specific control bits for Ethernet Units and the num-
ber of send/receive words
• Fixed cycle time setting in the PLC Setup
• File access in file memory, and the amount of data transferred to/from file
memory
• Event servicing for Special I/O Units, CPU Bus Units, Inner Boards, and
communications ports
• Use of peripheral and RS-232C ports
• Fixed peripheral servicing time in the PLC Setup
Note 1. The cycle time is not affected by the number of tasks that are used in the
user program. The tasks that affect the cycle time are those cyclic tasks
that are READY in the cycle.
2. When the mode is switched from MONITOR mode to RUN mode, the cycle
time will be extended by 10 ms (this will not, however, take the cycle time
over its limit).
The cycle time is the total time required for the PLC to perform the 5 opera-
tions shown in the following tables.
Cycle time = (1) + (2) + (3) + (4) + (5)
Details
Details
Details
Processing time and fluctuation cause
CS1-H CPU Unit: 0.3 ms
CS1 CPU Unit: 0.5 ms
Processing time and fluctuation cause
Total instruction execution time
Processing time and fluctuation cause
When the cycle time is not fixed, the time for step 3 is
approximately 0.
When the cycle time is fixed, the time for step 3 is the preset
fixed cycle time minus the actual cycle time ((1) + (2) + (4) +
(5)).
Section 10-4
497