Inactive Data Links - Omron C200HW-CLK21 Operation Manual

Communications Cycle Time
Calculation Example
8-2-2

Inactive Data Links

252
E: Total number of bytes in messages transmitted during the
communications cycle
The number of bytes in each message differs according to the instruction
being issued.
Instruction
SEND Number of words to be sent 2 +
18
RECV 18
CMND Number of bytes in command
data + 10
Communications conditions are as follows:
Transmission medium:
Baud rate:
Network parameters:
Max node address:
Polled nodes per comm cycle:
Event-frames per comm cycle:
Network configuration:
Total number of data link words:
Nodes that send messages:
Bytes in all messages sent:
In this example, A to E in the equation have the following values.
A: 8,000
B: 4
C: 8
D: 2
E: 4,024
The communications cycle time is thus as follows:
10 8,000 + 600 4 + 290 8 + 320 2 + 4 4,024 + 3,290 = 104,746 ( s)
105 (ms)
The following equations are used to calculate a communications cycle time
when the data link is inactive.
Wired Systems
Baud rate
2 Mbps 600 B + 110
1 Mbps 1,150 B + 150
500 Kbps 2,260 B + 230
Note B: Number of polled nodes per communications cycle
(value specified in the network parameter)
C: Number of nodes connected to network
D: Number of nodes that send messages during the
communications cycle
E: Total number of bytes in messages transmitted during the
communications cycle
When sent
14
Number of words to be received
2 + 14
Number of bytes in response
data
Twisted-pair cable
2 Mbps
Defaults
32
4
35
8 nodes
8,000 words
2 nodes
2,012 2 bytes
Equation
C + 320 D + 4 E + 2,290 ( s)
C + 360 D + 8 E + 2,690 ( s)
C + 440 D + 16 E + 3,490 ( s)
Section 8-2
When received