Alarm Contact Port On Acx1000 And Acx1100 Routers; Table 14: Alarm Relay Contact Functions - Juniper ACX1000 Hardware Manual

ACX1000 and ACX1100 Universal Access Router Hardware Guide

Alarm Contact Port on ACX1000 and ACX1100 Routers

18
The ACX1000 and ACX1100 router has four external alarm contacts (also known as
potential free contacts) for connecting the router to external alarm devices. The port
labeled uses a 15-pin D-type connector. The external alarm contact has 15 pins
ALARM
that accept a single core wire from external alarm devices. A DE15 alarm cable is required
to connect the ACX1000 and ACX1100 router to external alarm devices. Use the gauge
wire appropriate for the external device that you are connecting.
Whenever a system condition triggers an alarm, the alarm relay contacts are activated,
which in turn activates the external alarm devices. The alarm setting is open or closed.
You can connect and configure two output alarms and four input alarms. Two additional
output alarms are reserved and are used to indicate major and minor system alarms.
Each output and input alarm has two contacts for connecting the router to external alarm
devices. Contact 1 of each alarm can be configured as Normally Open [NO] or Normally
Closed [NC] through the CLI. Contact 2 of each alarm functions as a reference [REF] or
negative potential terminal for Contact 1 of the corresponding alarm and provides a
current path for external alarm devices.
the alarm contacts.

Table 14: Alarm Relay Contact Functions

Contact
Name Contact Name
Contact 1 Normally Open (NO)
Normally Closed (NC)
Contact 2 Reference (REF)
Figure 11 on page 19 shows an example of a wiring diagram for a simple output
alarm-reporting device. In this case the device is a light bulb that illuminates when the
device encounters a condition that activates the red alarm LED and relay contacts. The
alarm relay contacts can also be used to activate other devices such as bells or buzzers.
Table 14 on page 18 describes the functions of
Function
Current is not flowing through Contact 1 and Contact 2
[REF] when operating normally. When the current flows,
the closed alarm is generated.
Current is flowing through Contact 1 and Contact 2 [REF]
when operating normally. When the current stops
flowing, the open alarm is generated.
Provides the current path for the external alarm-reporting
device and functions as a reference or negative potential
terminal for Contact 1.
Copyright © 2013, Juniper Networks, Inc.