Omron SYSMAC CV Series - Cycle Time; Asynchronous Operation

464
The following parameters are not maintained when the PC is restarted.
1, 2, 3... 1. Error status (but the Error Log is maintained.)
2. Disabled access to I/O memory by IOSP(187)
3. Data displayed on I/O Control Units, I/O Interface Units, and Slave Units by
IODP(189)
4. Status of CPU Bus Unit Service Disable Bits (A015)
5. Status of Service Disable Bits in A017
6. Message data
7. I/O interrupt mask status
8. Scheduled interrupt interval data
9. Data Register contents
10. Execution status of differentiated status monitoring
11. Execution status of execution time measurements
12. Execution status of stop monitoring
13. Execution of the following instructions may not be completed depending on
how much of the instruction had been executed when the power interruption
occurred: FILR(180), FILW(181), FILP(182), FLSP(183), READ(190),
WRIT(191), SEND(192), RECV(193), CMND(194)
6-2 Cycle Time
Understanding the operations that occur during the cycle and the elements that
affect cycle time is essential to effective programming and PC operations. The
major factors in determining program timing are the cycle time and the I/O re-
sponse time. One cycle of CPU operation is called a cycle; the time required for
one cycle is called the cycle time. The time required to produce a control output
signal following reception of an input signal is called the I/O response time.
To aid in PC operation, the present and maximum cycle times are recorded in the
read-only section of the Auxiliary Area. The present cycle time is held in A462
and A463 and the maximum cycle time is held in A464 and A465.
6-2-1 Asynchronous Operation
In asynchronous operation, instruction execution and I/O refreshing are pro-
cessed in a cycle that is independent of the cycle for peripheral servicing
(CPU Bus Units, host interface, etc.). Since the cycles are independent, the
number of CPU Bus Units, host interface links, etc., that are connected to the
PC has no effect on the instruction execution cycle time.
Parameters Not Maintained
for Restart Continuation
Cycle Time Section 6-2