CHAPTER 2
Chassis Components and Descriptions
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MX104 Alarm Contact Port Overview on page 9
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MX104 LEDs Overview on page 11
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MX104 LEDs Overview on page 13
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MX104 LEDs Overview on page 15
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MX104 Clocking and Timing Ports Overview on page 17
MX104 Alarm Contact Port Overview
The MX104 router has four external alarm contacts (also known as potential free contacts)
for connecting the router to external alarm devices. The port labeled ALARM uses a 15-pin
D-type connector. The external alarm contact has 15 pins that accept a single core wire
from external alarm devices. A DE-15 alarm cable is required to connect the MX104 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. Table 4 on page 10 describes the functions of
the alarm contacts.
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