ABB AC 800F

4 Cabling the AC 800F
4-50
4.2.10.7 Max. permissible network length with 10BaseFL cable
The explanations in this section give only a short overview.
Observe the detailed information about how to design fiber optic
cable networks given in
Hirschmann GmbH & Co, Esslingen: Ethernet Manual,
ordering code 943 320-011
The principle of Ethernet data transmission with collision detection assumes a
maximum propagation delay on the system bus between two nodes. Exclusive use of
standardized 10Base2 and 10Base5 Ethernet components with max. cable lengths
and a maximum of 4 repeaters ensures that the specified delay is achieved. For
details see Section 4.2.12.
When using 10BaseFL components and network concentrators, the maximum
network length is determined in another way. In this case the permissible length
results from adding the propagation delays of the cables and electronic components.
The following rule is valid:
Maximum network length ≤
≤≤
≤ 4800 m
Consider the longest distance in the network. A propagation delay equivalent in
meters is assumed for the electronic components in the signal path. Refer to the data
sheets of the network components for the respective propagation delay equivalents
needed for calculation.
The following table gives the propagation delay equivalents for various components.
They were used for calculating the example below.
Network concentrator modules Delay equivalent
AUI network concentrator module 165 m
10Base2 network concentrator module 110 m
10Base5 network concentrator module 10 m
10BaseFL network concentrator module 30 m