CANOGA PERKINS 9140 Four-Port SNMP Managed Fast Ethernet Switch - Manual (Page 38)

3-12
3.2.8 Relay Contacts
The alarm contacts for the 9135 Two-Port Switch and the 9140 Four-Port Switch are located next to the fan
assembly on the rear panel and are shown in Figure 3-12. These contacts monitor fault conditions for each
port.
• Loss of link integrity (all except AUI)
• Remote Fault signaling (100BASE-FX when management is installed and Remote Fault feature is
enabled)
• Unit power fail
Figure 3-12. Relay Contacts on Rear Panel.
Note: The alarm contacts located on the rear of the 9135 Two-Port Switch and the 9140 Four-Port Switch
are relay contacts that can be connected to either open or close a circuit. They can be used to close a
circuit allowing current to flow to an alarm or alert system or indicate a logical 1 or 0 through the
presence or absence of a voltage.
The relay alarm contacts are illustrated in Figure 3-12. The interpretations of the alarms are as follows:
• NO This means the relay is open during normal operation and closed during a fault condition.
• COM The common pin between alarm contacts.
• NC This means the relay is closed during normal operation and open during a fault condition.
Note: All pairs of alarm cables should be twisted and the cable shield should be terminated at the users
site.
Formatted: Bullets and Numbering
Formatted
Formatted: Bullets and Numbering
Deleted: ¶