Inactive Data Links - Omron CS1W-CLK12-V1 Operation Manual

Communications Cycle Time
9-2-2

Inactive Data Links

Calculation Example
188
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
F: 7 × 8
The communications cycle time in token-ring mode is thus as follows:
9.1 × 8,000 + 1,740 × 4 + 960 × 8 + 1,100 × 2 + 4 × 4,024 + 2 × 7 × 8 +
4,800 = 110,648 ( µ s) ≅ 111 (ms)
And the communications cycle time in token-bus mode is as follows:
9.1 × 8,000 + 1,300 × 4 + 290 × 8 + 320 × 2 + 4 × 4,024 + 2 × 7 × 8 + 2,290
= 99,458 ( µ s) ≅ 100 (ms)
The following equations are used to calculate a communications cycle time
when the data link is inactive.
Token-ring Mode
1,740 × B +450 × C + 1,100 × D + 4 × E + 2 × F + 3,000 ( µ s)
Token-bus Mode
1,300 × B + 110 × C + 320 × D + 4 × E + 2 × F + 1,800 ( µ s)
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
F: Optical Fiber Cable transmission delay time
H-PCF cable: F = 7 × L µ s (L is the cable length in km.)
GI cable:
The number of bytes in each message differs according to the instruction
being issued, as shown in the following table.
Instruction
Number of words to be sent ×
SEND
2 + 18
RECV 18
CMND Number of bytes in command
data + 10
Communications conditions are as follows:
Transmission distance (with H-PCF cable): 8 km
Transmission speed:
Network parameters:
Max node address:
Polled nodes per comm cycle:
Event-frames per comm cycle:
Network configuration:
Nodes that send messages:
Bytes in all messages sent:
F = 5 × L µ s (L is the cable length in km.)
When sent
14
Number of words to be received
× 2 + 14
Number of bytes in response
data + 10
2 Mbps
Defaults
62
4
35
8 nodes
2 nodes
2,012 × 2 bytes
Section 9-2
When received