Mettler Toledo IND246 Guide D'installation page 38

IND246 Terminal Installation Manual
COM2 with Discrete I/O Connections
The COM2/Discrete I/O option board (Figure 2-25) is positioned in option position
1 on the main board, and provides the COM2 serial port with 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.
COM2
The COM2 port on the COM2/DIO option has the same connection as described in
the previous COM2 section. Refer to that section for details.
Active Input
Selecting the inputs as active (Figure 2-32) enables connection of switches or
other simple devices to trigger an input. No voltage is supplied by the external
simple device.
An example of how to wire to the active inputs is shown in Figure 2-26.
2-16
Figure 2-25: COM2 with Discrete I/O Option Board
NOTES:
1. VOLTAGE IS LOGIC LEVEL 5 VDC. LOW RESISTANCE
CONTACTS RECOMMENDED. MAXIMUM CABLE LENGTH:
20 FEET / 6 METERS.
2.
DO NOT BUNDLE INPUT WIRING WITH POWER WIRING OR
ANY OTHER HIGH ENERGY CABLES.
3.
SWITCHES MAY BE REPLACED WITH RELAY DRY
CONTACTS.
4.
WIRE SIZE: 18 AWG (0.832 mm
Figure 2-26: Active Input Connections
Outputs
Inputs
2
) MAXIMUM
2
24 AWG (0.205 mm ) MINIMUM