As the amplifiers do
eguide switch is pre-
selected by the use
control unit. The low
power alarms on b
amplifiers placed in the
transmit state. The
via the user interface
or from the N6143
With both amplifiers ope
RF output power, the
waveguide switch will remain as
the other amplifier for
potential faults
on, or its RF output
power drops below
alarm level), the other
amplifier takes co
t is used, an audible
alarm will indicate the fault
The amplifiers will remai
not recover and a fault
ccurs on the second amplifier it will not result in switching of the waveguide switch.
a 24V type and a closed tell-back contact within the waveguide
ould be used for the amplifier whose output is switched to the load. An open contact tell-back
e switch selected but will be typically 50-100ms.
1-pin amplifier control
onnector. Termination of the serial communications bus is dependent upon the length and type of
e used, and should follow normal transmission line practice.
not have a master/slave relationship, the position of the wav
r either manually, via the user interface or from the N6143
oth amplifiers should be set if required and then both
automatic mode enable (AUTO ENA) input is then selected
control unit to pass control of the switch to the amplifiers.
rating normally in the transmit state with >1W of
set. Each amplifier monitors the status of
. If the amplifier routed to the antenna develops a fault conditi
the low power alarm setting (1W minimum low power
ntrol, switching the waveguide switch. If the N6143 control uni
condition to the operator.
n in the automatic mode, but if the faulty amplifier does
o
he waveguide switch coil should be
T
switch sh
should be used for the amplifier switched to the antenna.
witching time is dependent upon the waveguid
S
The interface between the control unit and the amplifiers is via the local serial communications bus.
As the amplifiers do not contain transmitter or receiver termination, the local serial communications
bus should be fitted with 120R ±1%, ¼W carbon film or similar termination resistors between pin d
X+) and pin e (RX-), also between pin b (TX+) and pin c (TX-) of the 4
(R
c
cabl
Figure 5 Redundant switch operation
Notes:
A wiring schematic diagram is given in the appendices for the connection of two amplifiers, the N6143
control unit and a waveguide switch.
If the amplifier AUTO ENA line is not asserted, the RED FLT O/P will not be enabled. Consequently, if
an external controlling device other than the N6143 is used, the RED FLT O/P cannot be used to
trigger the amplifier switch-over. As an alternative, the SUM FLT IND multiplexed fault lines or
inverted XMIT IND outputs can be used as the trigger for the switch-over.
© e2v technologies (uk) limited 2010
DAS768892AA
Version
1,
page
15
