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SWITCHING
THRESHOLD
PORT 1
A/B SWITCH
PORT 2
PATENT PENDING
(–dB)
4.3.2
Entering A/B Switch Mode
To enter A/B switch mode, power-up the unit and hold the SWITCHING THRESHOLD switch
to the "down" position until the lower-case "c" appears on the threshold display.
Note: If necessary, the unit can be switched back to the redundant amplifier mode later by
holding the SWITCHING THRESHOLD switch in the "up" position while powering up.
The RDS memory retains the selected mode while the unit is shut off.
4.4
Setup for A/B Switch Mode Operation
Setup for A/B switch mode is accomplished by first selecting which port is to be configured.
After initial power-up, the front panel status should indicate normal and dual failure status. The
top and bottom segments of the 7-segment display indicate which port status is currently
displayed. After initial power-up, the display will alternately indicate status for port 1 and port 2
by flashing either the top or bottom segment for approximately two seconds while displaying
threshold and status information for the associated port (Port 1 or Port 2).
Port 1 can be configured by toggling the threshold switch to the "up" position. The display will
then lock on to the status indications for port 1. If no changes are made within 15 seconds, the
display will then revert to its alternating port1/port2 flashing display. While locked onto port 1,
the user should calibrate the base level of the receiver using the procedure described below.
After the RDS is calibrated, the user can lock onto the designated primary receiver/amplifier (A
or B) with the AMP SELECT switch, then set the desired threshold level with the SWITCHING
THRESHOLD toggle switch. The threshold set in this mode of operation will be the level below
which the calibrated signal must drop before switching from the primary to standby receiver/
amplifier. For example, if Receiver A is calibrated with a 40 dBmV power level and the
threshold is set for 3 dB down, the RDS will switch to Receiver B whenever the "A" signal level
falls below 40 - 3 = 37 dBmV. The above procedure is then repeated for Port 2 after selecting
Port 2 by pressing the threshold switch "down."
4.5
Output Calibration
Note: The calibration process will monitor the amplifier or receiver output level and set
the switch to expect that particular signal level.
A
B
AMP SELECT
Figure 17. RDS Front Panel With A/B Switch Mode Label Installed
A/B Switch Mode
—
NORMAL
CALIBRATION
OPERATING
MODE SELECT
ADCP-61-810 • Issue 4 • September 2004
SINGLE
LOSS OF
DUAL
FAILURE
INPUT
FAILURE
™
STATUS
10139-B
© 2004, ADC Telecommunications, Inc.
Page 15
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