Serial Plc Link Response Performance; Pulse Output Start Time - Omron CP1H-X40D Operation Manual

Computing the Cycle Time
External Interrupt Tasks
2-7-9

Serial PLC Link Response Performance

2-7-10 Pulse Output Start Time

Internal timer
Scheduled interrupt task
(2) When using input interrupt or pulse output 2/3 and analog input/output
(XA type only), pay attention to the possibility that timer interrupt cannot
be executed within short time interval.
The interrupt response time for external interrupt tasks depends on the Unit or
Board (CJ-series Special I/O Unit or CJ-series CPU Bus Unit) that is request-
ing the external interrupt task of the CPU Unit and the type of service
requested by the interrupt. For details, refer to the operation manual for the
Unit or Board being used.
The response times for CPU Units connected via a Serial PLC Link (master to
slave or slave to master) can be calculated as shown below. If a PT is in the
Serial PLC Link, however, the amount of communications data will not be
fixed and the values will change.
• Maximum I/O response time (not including hardware delay) =
Master cycle time + Communications cycle time + Slave cycle time + 4 ms
• Minimum I/O response time (not including hardware delay) =
Slave communications time + 1.2 ms
Here,
Number of partici- The number of slaves to which links have been established
pating slave nodes within the maximum unit number set in the master.
Number of non-par- The number of slaves not participating in the links within the
ticipating slave maximum unit number set in the master
nodes
Slave communications time × Number of participating slave
Communications
nodes + 10 × Number of non-participating slave nodes
cycle time (ms)
Slave communica- • Communications time set to Standard
24.6 + 0.494 × ((No. of slaves + 1) × No. of link words × 2 +
tions time (ms)
12)
• Communications time set to Fast
25.7 + 0.242 × ((No. of slaves + 1) × No. of link words × 2 +
12)
The pulse output start time is the time required from executing a pulse output
instruction until pulses are output externally. This time depends on the pulse
output instruction that is used and operation that is performed.
Instruction execution
Pulse output
Scheduled interrupt time
Software interrupt response time
Start time
Section 2-7
103