Calculation Example - Omron SYSMAC CS1W-RPT01 Operation Manual

Data Link I/O Response Time
Note
8-3-3

Calculation Example

PLC
C
L
K
#1
Input
Input LRXXXX
Communications Cycles
Time
Input ON Delay
Output ON Delay
Cycle Times
PLCs
CS/CJ-series PLCs
CVM1 and CV-series PLCs
C200HX/HG/HE PLCs
CQM1H-series PLCs
1. Use the above equations only if only one Controller Link Unit is mounted
on the PLC. If other CPU Bus Units are mounted on the PLC, obtain the
refresh times for each CPU Bus Unit and add to the above equations.
2. The execution of some items takes precedence over data link area refresh-
ing. For example, data link area refreshing will not take place during exe-
cution of the SEND(192), RECV(193), or FAL(006) instruction.
The data links of the Controller Link Unit require a slight time delay from the
time the data link area of one node is changed until this change is reflected in
the data link area at another node. This time delay is called the data link I/O
response time. The following is a calculation example of the maximum and
minimum I/O response times for the system configuration shown below.
CLK: Controller Link Unit
PLC
C
System configuration
L
K
#1
LRXXXX Output
No messages communications are performed.
A single Controller Link Unit is mounted to each
CPU Rack.
The data link I/O response time depends on the communications cycle time,
input ON delay, output ON delay, and the cycle times of the PLCs involved.
The values are detailed below.
Communications cycle time =
10 × (8 + 16) × 8 + 600 × 4 + 290 × 8 + 320 × 0 + 4 × 0 + 3,290
= 9,930 µ s ≅ 9.9 ms
The input ON delay is the time it takes for an input device to turn ON an input
to the PLC after receiving an input signal. In this system the input ON delay is
1.5 ms.
The output ON delay is the time it takes for an output device to turn ON an
output signal after receiving an output from the PLC. In this system the output
ON delay is 15 ms.
The cycle time of the PLC at node #1 is 25 ms.
The cycle time of the PLC at node #7 is 10 ms.
Words per data exchange
Approx. 7,800 words
Approx. 3,700 words
Approx. 4,000 words
Approx. 1,200 words
Baud rate:
Maximum node address:
Number of polled nodes per comm cycle: 4
Number of event-frames per comm cycle: 35
Nodes in network:
Nodes in data links:
Words sent in area 1:
Words in area 2:
Section 8-3
2 Mbps
32
8 nodes
8 nodes
8 words per node
16 words per node
259