Response Performance Of Serial Plc Links - Omron CJ2 - 02-2010 User Manual

12-2-8 Response Performance of Serial PLC Links

The response times for CPU Units connected via a Serial PLC Link (polling unit to polled unit or polled
unit to polling unit) can be calculated as shown below.
• Maximum I/O response time (not including hardware delay) [ms] =
Polling unit cycle time × 2 + Communications cycle time + Polled unit cycle time × 2 + Polled unit
communications time + 4 ms
• Minimum I/O response time (not including hardware delay) [ms] =
Polled unit communications time + 0.54 ms
Number of participating polled unit
nodes
Number of non-participating
polled unit nodes
Communications cycle time [ms]
Polled unit communications time
[ms]
CJ2 CPU Unit Software User's Manual
The number of polled units to which links have been established within the
maximum unit number set in the polling unit.
The number of polled units not participating in the links within the maximum
unit number set in the polling unit.
• With Two or More Polled Units
Polled unit communications time × Number of participating polled unit
nodes + 10 × Number of non-participating polled unit nodes
• With One Polled Unit
Polled unit communications time + 10 ms
• Baud rate set to Standard:
Polled unit cycle time + 0.286 × [(Number of polled units + 1) × Number of
link words × 2 + 12]
• Baud rate set to Fast:
Polled unit cycle time + 0.0955 × [(Number of polled units + 1) × Number
of link words × 2 + 12]
12 CPU Unit Cycle Time
12
12-15