Alarms - BW Broadcast TX5 FM Broadcast Transmitter Technical Manual

2.3

ALARMS

The transmitter has three alarms that can alert the broadcaster if one of the following fails:
R.F. POWER, PLL LOCK, MODULATION
The alarms when set are available on the back panel 9-pin D-type. Each alarm has an open collector (OC) and
a TTL level contact on the D-type. The alarm induced active open collectors can pull down any external signals
and the TTL outputs will provide a 5 Volt indication. The alarm is also visible if any RS232 monitoring (through
Windows Remote Control application or terminal software) is employed.
For the alarms to function correctly the transmitter must be left on the default menu screen. This is the screen that
displays frequency, R.F. power and peak deviation. To ensure that the alarm system functions correctly the trans-
mitter will return to the default menu screen if the LCD is left on another menu screen for more than 5 minutes.
R.F. POWER.
The R.F. power alarm will be set if the R.F. power falls below a threshold level during normal operation.
This threshold is set below the normal operating lowest wattage available from the transmitter. If you
require a different setting for the alarm, contact our tech dept. The alarm will only be set if the fault condi-
tion exists for sixty seconds or more. You will need to reset the transmitter to clear the alarm/s or you can
do it via RS232 connection.
PLL LOCK.
The PLL lock alarm will be set if the transmitters falls out of frequency lock during normal operation. The
alarm will only be set if the fault condition exists for sixty seconds or more. You will need to reset the trans-
mitter to clear the alarm/s or you can do it via RS232 connection.
MODULATION FAILURE.
The Modulation failure alarm will be set if during normal operation the peak deviation of the transmitter
drops and remains below 16 kHz. The 16 kHz alarm level allows the alarm to be set if the audio feed to
the transmitter fails even if the stereo pilot internal to the transmitter is still modulating the transmitter. The
alarm will only be set if the fault condition exists for sixty seconds or more. You will need to reset the trans-
mitter to clear the alarm/s or you can do it via RS232 connection.
MORE INFO ON ALARMS
The three alarms are available on the back panel D-type connector. The pin-outs are shown on the rear
panel diagram. The three alarms are available as TTL level and as open collector outputs. The TTL level
outputs are active high in the event of an alarm. The open collector outputs are ON in the event of an alarm
and will pull down any external levels. The open collectors can sink 100 mA MAX with an absolute maxi-
mum switched voltage of 25 volts.
The D-type connector can also supply 18 volts at 200 mA that can be used for pull-ups on the open collec-
tor alarm outputs and for your own external switching circuitry.
The RS232 interface provides the ability to reset the alarms either through Windows Remote Control appli-
cation or terminal software. More info is found in the following pages of the manual.
BW Broadcast can also customise the alarm / fault software to meet the requirements of major broadcast-
ers and networks or supply N+1 solutions. More information on this and other custom features can be
obtained from our technical department.
BW Broadcast technical manual
Installation and setup
Page 16