Technical Handbook

Table Of Contents
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Block Diagram:
Figure 9-14 Block diagram RCA1240C
Block schematic signal description:
Block Description:
CONTROL AND UARTS
This block interprets serial data from the ILScabinet and generates status outputs to front
panel LEDs, slave panel outputs, opto outputs and buzzer signal based on the received sta-
tus. Failure in data from ILS results in alarm condition. Discrete inputs from the front panel
keyboard, control/AUX inputs and slave panel (Ch. 9.2.5) are collected and sent fo the ILS
rack as serial data.
INTERFACE SELECT
These straps selects between telephone line and RS232 for interface with the ILS cabinet.
The default setting is line interface.
LINE DRIVER/MODEM
This block converts logic level serial signals to and from FSK level line signals.
RS232 DRIVER
This block converts logic level serial signals to and from RS232 level signals.
SIGNAL DRIVERS
This block drives the front panel LEDs, opto outputs and slave panel LEDs.
CONTROL INPUTS ILS control signals. Consists of INTERLOCK and TX_OFF.
OPTO OUTPUTS Optocoupler outputs. Collector/emitter for ALARM, NORMAL,
WARNING and STB_ALARM.
SLAVE_DIRECT_BUS Data interface to optional slave panel. Consists of open col-
lector outputs (ALARM, NORMAL, WARNING, STB_ALARM
and SLAVE_BUZZER) and active low inputs (ON_OFF,
CHANGEOVER and SILENCE).
Line
driver/modem
Telephone
line
Control
and
uarts
LED OUTPUTS
RC1241A
RS232
driver
RS232
Signal
drivers
SLAVE DIRECT BUS
RF1242A/B
Front panel
LEDs
AUX_IN
AUX_OUT
KEYBOARD INPUTS
RF1242A/B
Keys and
switches
CONTROL INPUTS
SLAVE DIRECT
INPUTS
SLAVE
LED
OUTPUTS
OPTO OUTPUTS
Interface
select
&
config
RST_SL_AURAL_ONLY
STATUS
ALARM
RST_RC_AURAL_ONLY
HBK546-2