ADC RF Worx, User Manual

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ADCP-61-810 • Issue 4 • September 2004
Page 1
© 2004, ADC Telecommunications, Inc.
1 GENERAL
The ADC RF Worx Redundant Switch, shown in Figure 1 , is designed for use in 19-inch or 23-
inch equipment racks. All RF signal connections to the switch are made through standard 75-
ohm BNC connectors (RDS-B) or F connectors (RDS-F) on the rear panel. All operating
controls and indicators are on the front panel.
The RF bandwidth used with this equipment is that of the CATV forward path video (i.e., 50 to
1000 MHz).
1.1 Redundant Amplifier Mode
In the “redundant amplifier” mode of operation, the function of the RDS is to monitor the RF
signal gain of an operating (primary) amplifier and switch to a backup (standby) amplifier if the
gain of the primary amplifier falls below a set point. When an amplifier gain failure occurs, the
RDS rapidly switches the input power and then the input and output RF connections from the
failed primary amplifier to its backup amplifier. Status and failure LEDs are mounted on the
front panel of the redundant switch. An RS-485 interface also provides amplifier calibration
data (i.e., date and time) and operating/failure status to a Windows 95/98/NT personal computer
(PC) equipped with switch monitoring software and appropriate interface cards. If the RF input
to the primary amplifier falls below a detectable level, the switch sends a Loss of Signal (LOS)
alarm to the PC but does not switch amplifiers.
Figure 1. Redundant Switch (RDS)
1.2 Dual A/B Switch Mode
In the “dual A/B switch” mode of operation, the RDS monitors the primary input signal,
automatically detects when the primary input signal has decreased in power (dBmV) more than
the threshold amount set on the front panel of the switch, then automatically switches to the
backup signal. In this mode, only the output of the receiver or amplifier is switched, not the
input
and output. This mode is used to provide redundancy to amplifiers or receivers used
anywhere in the forward path cable TV network.
OPER
ATIN
G
CALIB
RATIO
N
NOR
MAL
SWIT
CHIN
G
THRE
SHO
LD
(-R)
B
A
SING
LE
FAIL
URE LOSS O
F INPU
T
DUA
L
FAIL
URE
SELECT
SELECT
STATUS
9134-B
2A 240V
V: 38.4
–57.6
VDC/100/120/240
VA
C
Ø: 1
A: 1A MAX DC / 2A MAX A
C
HZ: 47
–63 HZ
UR
PATENT PENDIN
G