ABB AC 900F Mounting And Installation Instructions Manual page 94

Serial interfaces of the CPU module
Ethernet
The CPU module features several on-board Ethernet interfaces. As far as the
maximum line lengths in Ethernet networks are concerned, various factors must be
taken into consideration. With twisted pair cables (transmission rate of 10 Mbit/s
and 100 Mbit/s) for instance, the maximum length of one segment, i.e. the
maximum distance between two network components is limited to 100 m due to the
electric properties of the cable.
In addition, the length limitation for one collision domain must be observed. A
collision domain is the area within a network that may be affected by a potential
collision. However, this must only be taken into consideration if the components are
operated in half duplex mode, as the CSMA/CD access process is only used in this
case. If all components work in full duplex mode, no collisions will be caused.
94
Section 6 Wiring
M&I – AC 900F Controller