Synchronous Operation With A Sysmac Bus/2 System - Omron SYSMAC CV Series Operation Manual

I/O Response Time
Maximum I/O Response
Time
Cycle
Buffer in Master
Input signal
Output signal

6-5-5 Synchronous Operation with a SYSMAC BUS/2 System

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The PC takes longest to respond when the relevant instruction is executed just
prior to SYSMAC BUS/2 refreshing. In this case the CPU does not execute the
instruction with the new input bit status until the next cycle. This situation is illus-
trated below.
Cycle time
Program
execution
Input ON delay
I/O response time
Maximum I/O response time = input ON delay
+ communications cycle time
+ 15 ms + output ON delay
Maximum I/O response time = 1.5 + (5 8) + 20 +2 + 15 + 15 = 93.5 ms
Here, we'll compute the minimum and maximum I/O response times for a
CV1000 that is set for synchronous operation and controls a SYSMAC BUS/2
System. Both the input and output are on Units connected to Slave Racks. The
PC receives data from the Master once each cycle. The Master waits to transfer
to the PC after refreshing.
The data in the following table is used to produce the minimum and maximum
cycle times shown calculated below.
Input ON delay
Cycle time
Output ON delay
Communications cycle time
Program
execution
Communications
cycle time
8 + cycle time + remote refresh time
1.5 ms
20 ms
15 ms
5 ms (one group 3, 58M Slave)
Section 6-5
I/O refresh
Output ON delay