User`s manual

H.323 User's Manual 3. Installing the Mediant 1000
Version 5.0 39 December 2006
3.4.2 Setting up a Dry Contact Relay Alarm System
The dry contact ports I and II located on the gateway's CPU module (refer to Figure 2-1 on
page 27), allows you to connect the gateway to an external audible or visual alarm system.
The table below describes the operational status of these dry contact ports.
Table 3-1: Dry Contact Operational Description
Port Normal State Alarm Severity State
I
During normal operation, the dry contact is
open.
If a Major alarm is generated, the dry
contact closes.
II
During normal operation, the dry contact is
open.
If a Critical alarm is generated, the dry
contact closes.
You can view a detailed description of these alarms by accessing the Active Alarms Table
(refer to Section 5.10.4 on page 202) in the gateway's embedded Web server.
The external alarm system is connected to the Mediant 1000 gateway's dry contact
connector on the CPU module, using the supplied dry contact wires’ mate (refer to Figure
3-5). The mate provides four spring-cage terminal block connector labeled 4, 3, 2 and 1
(from left to right). These connections correspond to the four pins of the dry contact
connector on the CPU module.
You need to supply your own wiring (for connecting to the mate’s spring-cage connections)
as well as a visual and/or audible alarm system attached at the other end of the wires. The
dry contact connector suites wire sizes in the range 20 to 28 AWG. In addition, the dry
contact system can receive a current of up to 1.5 A.
Figure 3-5: Dry Contact Wires’ Mate
Note: The dry contact alarm provided on the CPU card should be connected only
to SELV (Safety Extra-Low Voltage) non-energy hazard sources (Class 2)
as per UL60950 and EN60950.