the digital board.
-12V = Rx
4
Power
B+ power connection.
DC +12V nominal
5
Serial Data Out
(TXD)
Serial data output for radio control or program.
It uses asynchronous data format.
TTL level
O/P
6 Busy
(CD)
Logic level output from SD-170 to indicate whether a
carrier is present or not
Note : If you installed an option modem board, you
can select RS-232 signal level by Jumper (CON407,
r
) on the digital board.
TTL level
0V = carrier
5V = no carrier
RS-232 level (option)
+12V = carrier
-12V = no carrier
O/P
7 Microphone
filtered
audio IN
This signal is injected to the MOD at the point through
audio-amplification, pre-emphasis and high pass filtering
where sub-audio tone is mixed with audio.
Audio
1KHz audio at 60% peak
system deviation
input level =
6 to 8Vrms
I/P
8
Serial data IN
(RXD)
Serial command or data input for radio control or program.
It uses asynchronous data format.
TTL level
I/P
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 @ 8
Ω
O/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
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.
