Theory Of Operation - Harris ZX2500 Technical Manual

ZX Series
Table A-2 List of transmitter log messages.
RF MUTE END
REVERSE
FOLDBACK
REVERSE
FOLDBACK OK
RESTARTS
EXCEEDED
EXCITER FAULT
EXCITER OK
REMOTE
DISABLED
REMOTE ENABLED
EXCITER B
SELECTED
EXCITER A
SELECTED
FM MODE
SELECTED
FM+HD MODE
SELECTED
HD MODE
SELECTED
SL MODE
SELECTED
A.4

Theory of Operation

The FM Web Remote features a Microchip PIC18F97J60 microcontroller running a
modified version of the Microchip V4.02 TCP stack and a custom made application to
interface to the ZX series of transmitters. An on-board real time clock with 3V coin-
cell battery maintains the current time, even in the absence of AC mains power. An on-
board EEPROM maintains non-volatile storage of the transmitter log and various
configuration settings. An on-board RJ11 jack provides for in-circuit programming in
the factory. Should a software upgrade be required in the field, the preferred method is
to unplug the card from the I/O board and plug in a replacement board sent in advance
from the Harris factory. A small green LED at the lower edge of the card blinks once a
second when the web remote is operating correctly. This LED is not visible from
outside the amplifier chassis, but can be used to assess the functioning of the web
12/20/11
WARNING: Disconnect primary power prior to servicing.
External mute line opened again.
Transmitter output power was automatically reduced due to high reverse power
(VSWR) measured at output.
Reverse foldback condition cleared.
Auto-restart circuit locked out due to multiple unsuccessful restart attempts.
Exciter reported an internal fault or an exciter switchover occurred because of a
fault condition.
Exciter fault condition cleared.
Amplifier chassis was placed in "local" REMOTE DISABLED mode via switch
on reverse side of front door controller board.
Amplifier chassis was returned to REMOTE ENABLED mode.
Exciter main/alt switcher switched over to exciter A.
Exciter main/alt switcher switched over to exciter B.
Transmitter was switched to FM mode by Flexstar exciter.
NOTE: When no Flexstar exciter is present, the transmitter is hard-wired perma-
nently into FM mode via shorted pins on the exciter interface cable.
Transmitter was switched to FM+HD mode by Flexstar exciter.
The transmitter switched to HD mode by Flexstar exciter.
The transmitter switched to SL mode by Flexstar exciter.
888-2595-001
Appendix A - FM Web Remote Option
A-11