Allied Telesis IE340 Series, Руководство по установке, Страница: 41 / 136

Chapter 1: Overview
41
Alarm Out Connector
The switch has a 2-pin Alarm Out (ALM OUT) connector on the top panel
for an external alert device. The switch can use the device to alert you to
alarm conditions, such as power supply failures or ports without links. Here
are two examples of alert devices for the Alarm Out connector:

LEDs

Buzzers
The switch does not supply power on the Alarm Out circuit. Instead, the
circuit is an on or off dry contact relay. When an alarm occurs, the switch
changes the circuit from closed (on) to open (off). The circuit remains open
until the alarm is resolved, at which point the switch automatically closes it
again. The processes to resolving alarms can vary.
The external alert device has to provide the necessary power for the circuit
and be able to monitor the circuit for when it is closed or open. Here are
the power specifications for the circuit:

30VDC maximum

0.5A maximum
Caution
The external alert device must not exceed the above specifications.
The Alarm Out connector can be damaged by devices that exceed
the specifications.
 E119
You use the ALARM FACILITY RELAY command to specify the alarm
condition that opens the Alarm Out circuit. Examples of alarm conditions
are power supply failures, ports without links, and loop detections. For
instructions on the command, refer to the
Software Reference for IE340
Switches
.
An example of the feature is illustrated in Figure 10 on page 42. The Alarm
Out connector is attached to a blue LED alert device. The alert device is
configured such that its LED is off when the circuit is closed and on when
the circuit is open.
Now assume you want the switch to open the circuit and activate the LED
on the alert device whenever any port on the switch does not have a link to
a network device. Here are the ALARM FACILITY RELAY commands:

IE340-20GP:
awplus(config)# alarm facility link-down
port1.0.1-port1.0.20 relay