ADCP-61-813 • Issue 2 • February 2005
Page 12
© 2005, ADC Telecommunications, Inc.
Normal operation is with the A channel as primary and the B channel as backup. If input
channel B is manually selected from the front panel the output will be unmonitored by the
system and a LED on the front panel labeled “MANUAL” will indicate this status.
5.2.1
Failure Detection
When failure of the primary input channel A is detected, the system closes the dry contacts on
alarm relay, lights the red FAILURE LED on the front panel, and communicates failure to the
SWATCH software (if available).
5.2.2
Threshold
To prevent the system from chattering, the switching threshold (to backup/return from backup)
should be set to different levels. The difference should be half of the threshold setting to a
maximum of 2 dB.
Changing the threshold will cause switching if appropriate to the current signal level.
5.2.3
Switchback
Once the return of an acceptable signal to primary input channel A is detected, the system
monitors that signal for a full 15 seconds before switching back to channel A. During this time
the red FAILURE LED on the front panel will blink to indicate that the switchback is pending.
5.2.4
Clearing Signal Failure
To clear a failure on the RDS-AS and open the alarm relay contacts on an unused port, perform
the following procedure.
1. If the channel (port) in question was previously calibrated, follow the reset procedure
below. If not, proceed to step 2.
2. Toggle to channel B to clear the failure status-the FAILURE LED should extinguish.
5.2.5
System Reset Procedure
Use the following procedure to clear all threshold settings and all calibration info. This
procedure should be used when re-deploying the RDS-AS to a different location or application.
1. Power down (unplug) the RDS-AS and remove all power sources.
Note:
This system only monitors the signals of the A input channels for both ports 1 and 2.
The B input channels are not monitored and there is no auto-switching capability. A faulty
signal to input channel B will not be detected.
Note:
It is normal for the CALIBRATION LED to be flashing.
