188
Communications Cycle Time
Section 9-2
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)
9-2-2
Inactive Data Links
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:
F = 5
×
L
µ
s (L is the cable length in km.)
The number of bytes in each message differs according to the instruction
being issued, as shown in the following table.
Calculation Example
Communications conditions are as follows:
Transmission distance (with H-PCF cable):
8 km
Transmission speed:
2 Mbps
Network parameters:
Defaults
Max node address:
62
Polled nodes per comm cycle:
4
Event-frames per comm cycle:
35
Network configuration:
8 nodes
Nodes that send messages:
2 nodes
Bytes in all messages sent:
2,012
×
2 bytes
Instruction
When sent
When received
SEND
Number of words to be sent
×
2 + 18
14
RECV
18
Number of words to be received
×
2 + 14
CMND
Number of bytes in command
data + 10
Number of bytes in response
data + 10
Summary of Contents for CS1W-CLK12-V1
Page 3: ...iv ...
Page 5: ...vi ...
Page 9: ...x TABLE OF CONTENTS ...
Page 11: ...xii ...
Page 59: ...42 Component Names and Functions Section 3 1 Dimensions Unit mm ...
Page 62: ...45 Component Names and Functions Section 3 1 Dimensions Unit mm ...
Page 91: ...74 CVM1 and CV series Optical Ring Controller Link Units Section 4 2 ...
Page 108: ...91 Setting Data Links Section 5 2 Device Information Setting Data Link Tables ...
Page 125: ...108 Checking Data Link Status Section 5 4 ...
Page 181: ...164 Setting Routing Tables Section 7 4 ...
Page 199: ...182 Memory Areas Related to Duplex Operation Section 8 6 ...
Page 275: ...258 Handling Precautions Section 10 7 ...
Page 298: ...281 CS series Optical Bus Controller Link Units Appendix C Dimensions Unit mm 101 35 130 ...
Page 299: ...282 CS series Optical Bus Controller Link Units Appendix C ...