User's Manual

VI-6
Remote Port
The remote port allows external control of the transmission system via the DB25 connector on
each enclosure. All functions on the remote port are simply hard-wired or paralleled to existing
wiring to provide a secondary method of control to the user, and are activated as follows:
pin 1: ground to reset microcontroller, float otherwise
pin 2: ground for 2 seconds to toggle carrier on/off, float otherwise
pin 3: common ground
pin 4: DC power supply sample
Enclosure Interfacing
In the event of a fault in the combiner/filter enclosure, for example high reflected power or
overdriven output levels, the power amplifier enclosures need to know that there is a fault. A
DB9 cable accomplishes this by sending a fault signal from the combiner/filter enclosure to
indicate to the power amplifier enclosure that action may need to be taken. Specifically, the
shutdown circuitry on the combiner/filter enclosure’s control PCB sends a ground signal through
the DB9 to one of the optoisolated inputs on the power amplifier’s control PCB. The power
amplifier control PCB, in turn, then sends its shutdown voltage out to disable the driver and turn
off the carrier.