Specifications

19
Receiving Command & Data
Mode
Command
(BYTE0)
Data
(BYTE1)
Check sum (BYTE2)
: Command + Data
0xaa ACK N/A 1 Process Complete
Commands
0x55 NACK N/A
Table 3.4. Composition of response commands
Note)
This command is return signal for receiving command.
If Byte2 and sum of Byte0 and Byte1 among received data are same, Radio would
send ACK data and execute command. If not, Radio sends Nack data.
User would go into next step if receives ACK data. If receiving Nack data, user should
send command again.
example) If user changes from 1
st
Channel to 2
nd
Channel,
user should send Channel Change Command ( 0x64,0x02 , ( 0x64 + 0x2 ) ) to Radio.
If Byte2 and sum of Byte0 and Byte1 among received data are same, Radio sends
ACK data to user and goes to 2
nd
channel. If not, radio would send Nack data.
Status indicators and audible alert tones
SD-160 series data radio has a sophisticated microprocessor control which provides a range of
LED displays. LED displays operation mode, current status of radio, warning, and etc. Moreover,
if you connect the Speaker filtered OUT (Pin 9 of DB-15 connector) to an external speaker, you
can hear audible tones under the following conditions:
• Attempt to transmit on a channel which is already in use when busy channel lockout option
has been programmed
• Transmission time has exceeded time-out timer programmed length
• The other group or people has finished transmission using repeater
See the status indicators and audible alert tones chart (Table 2.5.) for full specification.