Westermo U100 - Manual (Page 11)

OnTime Industrial Ethernet
100 Series
V 1.0
- 11 -
Section 1.4 (Cont)
Twisted Pair Port Specification
Auto MDX/MDIX
The complete range of OnTime Switches automatically detects the transmit and receive
copper pairs used in a patch cable. This eliminates the need to source the two types of patch
cable (crossed and straight through) highlighted above and therefore reduces the cost of
carrying two types of spares. This feature cannot be deactivated.
Electrical Isolation
The copper (TX) ports incorporate high electrical isolation between the signal lines and the
internal electronics. In addition, the switch can also withstand over 500 Amps through the
shield for short periods of time (20-30mS) without effecting the operation and communication
of the Switch. However, this is not advisable. Fibre optical cables should be used in such
environments. Each TX port is isolated to chassis and other ports. Isolation is rated 1500Vrms
(1 minute).
Auto-Negotiation
Auto-Negotiation is a protocol that controls the speed and duplex of a copper cable when a
connection is established between two Ethernet devices. Auto-Negotiation detects the various
modes that exist in the device on the other end of the cable and highlights its own abilities to
automatically configure itself. Therefore, it will automatically operate at the highest
performance in relation to speed and duplex. This allows simple and automatic connection of
devices that support a variety of modes from a variety of manufacturers. The auto-negotiation
protocol only functions on copper ports.
As standard the range of OnTime Switches are shipped with the Auto-Negotiation feature
enabled. However, if required a manual configuration process is possible using the
push buttons. These are located on the front panel of the Switch.