
ADCP-61-819
•
Issue 1
•
July 2000
Page 8
© 2000, ADC Telecommunications, Inc.
3.2 Connecting the Redundant Amplifier Switch to a Computer
Connect RS-485 interface cables from a personal computer (PC) to the C IN and OUT
connectors on the rear panel of the switch. This connection can be via a daisy chain to/from
other switch panels. (See
Figure 9
.)
Note:
No more than 32 RDS units should be attached to a PC due to signal fan out
considerations.
RS-485
IN OUT
RS-485
IN OUT
RS-485
IN OUT
REMOTE
MONITOR
UP TO FOUR
RS-485 BUSES
UP TO 32 REDUNDANT
AMP SWITCHES IN
EACH DAISY CHAIN
9402-A
Figure 9. Daisy Chained Redundant Amplifier Switch Units
3.3 Alarm Wiring
Connect two 22-26 AWG wires to the alarm terminals at the rear panel labeled ALARM NO
(normally open) and C (common). (See
Figure 10
.) Connect the other ends of the wires to the
alarm panel at the installation location.
NO C
SPARE
ALARM
IN 2
VDC
-48
IN 1
14956-A
Figure 10. Terminal Block for Alarm and DC Power Connections
Warning
:
The Redundant Amplifier Switch is factory set for –48 VDC or 120 VAC operation.
For 240 VAC operation, refer to subsection 3.3, 220 to 240 VAC Operation, below.
Caution
:
The +24 VDC connections available for powering external amplifiers are unfused, so
extreme care must be taken in ensuring the +24 VDC power source and/or the external
amplifiers have built-in fuse protection.