Switches And Led Indication; Switches On The Field Terminal Board; Sw1 - Elster 6 Series Wiring Instructions

Switches and LED Indication

6
6 Switches and LED Indication

6.1 Switches on the Field Terminal Board

The field terminal board contains four switches, SW1 to SW4 (see Figure
6-1) to control communication lines and power input.
SW3
SW2

SW1

SW4
Figure 6-1: Switches on the Field Terminal Board
6.1.1 SW1
This switch is placed for the line termination of the serial communication
lines (see Table 6).
Every transmission line has to be terminated with the right impedance.
Certainly with long lines, like with RS 485 connections, a correct line
termination is important. In transmission lines without termination, the signal
reflects at the end of the cable. This reflection interferes with the original
signal so a cacophony of signals is seen at the receiver.
Page 20 of 31 Wiring Instructions UFM Series 6