Mettler Toledo IND131 Installationshandbuch Seite 51

IND131/IND331 Terminals Installation Manual
Discrete I/O (Relay) Connections
The relay output version of the COM2/Discrete I/O option board (Figure 2-41)
provides two isolated inputs and four dry-contact normally open relay outputs. The
inputs can be selected as either active or passive based on the position of the slide
switch on the board.
Active/Passive
slide switch
Figure 2-41: COM2/Discrete I/O (Relay) Option Board
Active Input
Selecting the inputs as active enables connection of switches or other simple
devices to trigger an input. No voltage is supplied by the external simple device.
The active and passive positions of the selector switch are shown in Figure 2-42.
Active Position Passive Position
Figure 2-42: Active/Passive Input Switch
2-27