Epson RC700, Руководство пользователя

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2. Installation
20 RC700 / RC90 Option Fieldbus I/O Rev.14
Maximum Network Length (Maximum Trunk Length)
The maximum network length is the longest distance either between terminating resistors
or between the two most distant nodes on the network.
Terminating
Resistor
Trunk Line
The longest distance is the maximum network length.
Terminating
Resistor
The maximum network length is determined by the type of cable and the baud rate.
Baud Rate
Maximum Network Length
Thick Cable Thin Cable
500 kbps
250 kbps
125 kbps 100 m
250 m
500 m 100 m
100 m
100 m
Both Thick Cable and Thin Cable can be combined and used for trunk lines. In this case,
the maximum network length is calculated using the following formulas.
Baud Rate Maximum Network Length
500 kbps Thick Cable Thin Cable Length ≤ 100m
250 kbps Thick Cable 2.5 × Thin Cable Length ≤ 250m
125 kbps Thick Cable 5.0 × Thin Cable Length ≤ 500m
Drop Line Length
Drop line length is the distance from a branch on the trunk line to the end of that branch.
Trunk Line
2 m
4 m
3 m
1 m
1 m
Node 1 Node 2
Node 3
In the figure above, each drop line length is as follows:
Drop Line to Node 1: 4 m
Drop Line to Node 2: 6 m
Drop Line to Node 3: 6 m
One drop line length should be 6 m or less.