CANOGA PERKINS 3240S SNMP Managed Fiber Optic Multiplexer - Manual (Page 30)

3240S F I B E R O P T I C M U L T I P L E X E R
3240S Fiber Optic Multiplexer
2.4 Redundant Optics Operation
Redundant Optics can be controlled by the NMS in parallel with manual switch actuation. Control of the Redundant Optics
however is strictly maintained via NMS or manual operation. Control violations will result in a conflict between the automatic
and manual operation where one of the methods will not actuate the desired function.
Via the NMS, if the MANUAL-PRIMARY mode has been selected, the manual switch cannot
override this selection. Therefore when the NMS is being utilized for control, the manual switch
must be set to the NORM and AUTO positions. Conversely, when the switch is being manually
operated, the Mode switch option via the NMS must be set to AUTO and the Redundant
Optics Switch option to NORM.
2.4.1 Controls and Indicators
The redundant operating mode is set with the 3-position PRI/AUTO/SEC switch. The PRI and SEC positions force operation
of the 3240S on the primary or secondary links, respectively. The switch is principally used to reset an alarm condition by
cycling from AUTO to either PRI or SEC, then back to AUTO. Secondly, it is used as an aid for maintenance, allowing the user
to easily verify the integrity of each link. AUTO, or Automatic Mode, is the normal operating mode. This switch can be
controlled manually or via the NMS. If control is to be set via NMS, the switch must remain in the AUTO position.
Four LEDs related to fiber optic redundancy are provided on the Front Panel. This allows for easy identification of system
status. Illumination of the AUTO LED indicates operation is in the automatic mode. Illumination of the SEC Indicator signifies
operation is on the secondary fiber optic link. Illumination of the ALM Indicator signifies either a failed back up fiber optic
link, which is the link not in use, or that an automatic link switch over has occurred. Illumination of the Backup Indicator
signifies a failure of the back up fiber optic link.
The Alarm Relay Jack (ALM), located on the Rear Panel, provides a relay contact for a remote alarm connection. The Alarm
Relay reflects the same condition as the ALM Indicator.
2.4.2 Functional Description (Managed Operation)
The AUTO Mode is used for normal operation. When the AUTO Indicator is illuminated and the Backup, SEC and ALM
Indicators are extinguished, the system is operating on the Primary Link and both fiber optic links are operational.
If a failure occurs on the Secondary Link, the receiving end of the link will indicate the malfunction by illuminating the Backup
and the ALM Indicators. The transmitting end of the link will have the ALM Indicator (only) illuminated. This condition will
continue until the failure has been rectified and the alarm is reset. The Alarm Relay follows the ALM Indicator. The NMS will
activate the Fault Relay, also known as the Alarm Relay, and the ALM Indicator illuminates at the remote 3240S. The alarm
condition will remain until the multiplexers are reset. This allows the user to identify that an alarm condition is, or was present.
If a failure occurs on the Primary Link, the receiving end of the link will switch operation to the Secondary Link, and indicate
the failed condition by illuminating the Backup, SEC and ALM Indicators. The NMS will activate the Fault Relay, also known
as the Alarm Relay, and the ALM Indicator illuminates at the remote 3240S. Once the condition causing the failure on the
Primary Link is rectified, the 3240S will switch operation back to the Primary Link. The alarm indication will remain until the
multiplexers are reset. This allows the user to identify that an alarm condition is, or was, present.
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