DNL-4 Waveguide Switch
Operation
The DNL-4 contains one
coax switch. Its designation is S2 on the front
panel.
Note
that coax switches with manual override OR coax
switches without manual override may be
purchased. All Coax switches are Latching type
with position indicators. Coax switches without
manual override are less expensive.
The
wave guide switch (not normally included) is
external to the controller.
The S1 S2 combination of
input and output switches are electrically
ganged. This means that the position commands
are sent out to the 2 switches at the same time,
from the same source. Whenever the controller
switches S1 to a position, the input coax switch
that is internal to the controller will receive
the same position command. That is why it is
necessary for the wave guide switch and the coax
switch to have the same switching voltage and
polarity.
For
most applications it is assumed that the
operating voltage of the switches is between
20-30Vdc, with the switch common being
“Negative”. That means that the command voltage
is “positive”. The DNL-4 uses a 28Vdc supply for
switch operation to reduce the effects of cable
losses due to length and gauge of the switch
cables being used.
Position Indicators are
different.
Each of the 2 switches in
the system have two position indicators
(position 1 and position 2 indicators). Each of
these indicators are independently displayed on
the front panel. Under normal operation, both
the input and output switches will always be in
the same position. It should be noted that for
automatic switching purposes, the position
indicators from the waveguide switch are used by
the controller to determine switching commands.
Should
the input wave guide switch and output coax
switch be in different positions, those
positions will be displayed on the front panel.
All
coax switches used are of the “Latching” type.
This means that the switches maintain their
position in the event of the controller being
turned off.
All
commands out to the switches are of a momentary
nature. A command only exists for about 0.5
seconds. This facilitates the use of the
mechanical override knobs that may be present on
the switches.
All
switches are 4 port devices. When a switch has a
position, then two diagonally opposite LEDs
should be lit on the front panel at the same
time. A front panel switch display (the 4 LEDs),
should always have 2 opposite leds lit. Of
course if the switch is not connected, then all
LEDs should be “off”.
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