2. Installation
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.
The longest distance is the maximum network length.
| Trunk Line |
Terminating | Terminating |
Resistor | Resistor |
The maximum network length is restricted by the type of cable and the baud rate.
Baud Rate | Maximum Network Length | ||
Thick Cable | Thin Cable | ||
| |||
500 kbps | 100 m | 100 m | |
250 kbps | 250 m | 100 m | |
125 kbps | 500 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 Length + Thin Cable Length ≤ 100m |
250 kbps | Thick Cable Length + 2.5 × Thin Cable Length ≤ 250m |
125 kbps | Thick Cable Length + 5.0 × Thin Cable Length ≤ 500m |
Drop Line Length
The drop line length is the distance from a branch on the trunk line to the end of that branch.
| Trunk Line | |
| 2 m |
|
| 1 m | 4 m |
1 m | 3 m | Node 3 |
Node 1 | Node 2 |
|
In 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 6m or less.
14 | Fieldbus I/O Rev.6 |
