Installation guide

VAR4 / VAR12 / VAR20 - Product Description
All ports on the expand units are opto-isolated interfaces. The base VAR4 unit has two types of control ports;
one is an opto-isolated interface, the other is an analogue port.
The following sections describe the characteristics of the ports.
Table 4 VAR Router Control Ports
VAR Port Type Control Port Number Contacts
VAR4 Analogue Base Unit - Port-1 1 – 10
Opto-Isolated Base Unit - Port-2 11 – 22
VAR12 Analogue Base Unit - Port-1 1 – 10
Opto-Isolated Base Unit - Port-2 11 – 22
Opto-Isolated Expand Unit 1 - Port-1 23 – 31
Opto-Isolated Expand Unit 1 - Port-2 32 – 42
VAR20 Analogue Base Unit - Port-1 1 – 10
Opto-Isolated Base Unit - Port-2 11 – 22
Opto-Isolated Expand Unit-1 - Port-1 23 – 31
Opto-Isolated Expand Unit-1 - Port-2 32 – 42
Opto-Isolated Expand Unit-2 - Port-1 43 – 51
Opto-Isolated Expand Unit-2 - Port-2 52 – 62
3.7.1 Analogue Interface
Contacts 1 to 10 only use a non-isolated analogue interface with an internal pull-up to 5 V. The analogue
interface operates in two modes: ‘non-monitored’ and ‘monitored’. Each contact is individually selectable
between these two modes.
3.7.1.1 Non-monitored Contact Closure to Ground
It may be used to interface a simple contact
closure to ground.
ROUTER
ANALOGUE
CONTACT
INPUT
Cabling to Contact
+5V
4k7 ohms
0V
THRESHOLD= 2.5V
Issue: 03 complete, approved
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