Service manual

Service Manual SD170E Series
Page 30 of 44
9
Speaker filtered
OUT
Audio output from the audio
amplifier.
It‟s filtered by tone-filter, de-
emphasis circuit.
Audio
1KHz audio at 60%
peak system
deviation produces
Nominal 1Vrms @
8Ω
I/P
10
Serial data IN
for option
modem
The Serial data to be transmitted is
input to this pin. It‟s only available
when option modem board is
installed. Inputted data are
modulated by modem IC and then
injected to MOD.
It uses asynchronous data format.
RS-232 level
I/P
11
Serial data Out
for option
modem
The recovered asynchronous serial
data output from the receiver. It‟s
only available when option modem
board is installed. It uses
asynchronous data format.
RS-232 level
O/P
12
Serial data busy
for option
modem
(reserved)
To eliminate data loss according to
buffer overrun of slave MCU‟s
memory, it indicates buffer status.
RS-232 level
O/P
13
GPS data input
Data input for initial setting of GPS
module.
It follows NMEA 0183 format and
uses asynchronous data format.
TTL level
I/P
14
Ground or DGPS
data input with LKG
removed.
Data input for DGPS Correction of
GPS module. It follows NMEA 0183
format and uses asynchronous data
format.
TTL level
I/P
15
GPS data
output
Position data output from the GPS
module. It follows NMEA 0183 format
and uses asynchronous data format.
TTL level
O/P
Note: When using GPS, the ground connection must be made using the outer shell of the DB-15
connector. Make sure the securing screws are tight on the connector when installing it to the unit.