Adtran 550 用户指南

ATLAS 550 System Manual

Section 2  Engineering Guidelines

61200305L2-1B

© 2004 ADTRAN, Inc.

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This connection alerts the user when a selected external alarm condition exists. This connection could be 
used to monitor a UPS with dry contacts or another ATLAS 550. The 2-pin, removable terminal block 
connects with external wiring. Refer to DLP-14, Connecting the Alarm Contacts, for detailed instructions. 
Clear the alarm condition by pressing the 

 switch located on the front panel of the ATLAS 550. 

Table 6 shows the pinout for the External Alarm Relay connector. 

This connection alerts the user when a selected alarm condition exists. The 4-pin, removable terminal 
block connects with external wiring. Refer to DLP-14, Connecting the Alarm Contacts, for detailed 
instructions. Clear the alarm condition by pressing the ACO switch located on the front panel of the 
ATLAS 550. Table 7 shows the pinout for the Alarm Relay connector.

The ATLAS 550 provides two Network Interface Slots that allow different types of interfaces to be used. 
Available Network Interface Modules include the following:

•

•

•

•

1

ALARM OUT Outputs EIA-232 level signal for connection to external alarm contacts.

2

ALARM IN

Monitors signal coming from external alarm contacts.

1

NORMALLY CLOSED (NC)

Opens when a selected alarm condition is present.

2

NORMALLY OPEN (NO)

Closes when a selected alarm condition is present.

3

COMMON (COM)

Common connection between external circuitry and NC or NO 

terminal.

4

CHASSIS GROUND (GND)

Ground connection.