Maxon SD-171E Operator's manual

SD-171E / SD-174E
Data Radio
User Instruction Manual

2
About your SD-170E Series Data Radio
The SD-170E Series of RF Link Modules utilize the latest technology in their designs and manufacturing. SD-170E models
are Phase Lock Loop Synthesizer (PLL) / microprocessor controlled and offers 1/ 5 watt (Low / High) programmable output
power with 16-channel capability. Multiple functions including 1200 to 9600 baud rates, AC and/or DC audio coupling,
GMSK, FFSK and FSK modulation are standard in these fully programmable RF Link Module units. Programmable sub-
audio squelch system (CTCSS & DCS) and two-tone squelch system are added to the signal level detect squelch system
(RSSI). GPS Data handling is provided to interface and control an internal GPS receiver.
To assure satisfaction from the radio, we urge you to thoroughly read the operation and function information in this manual
before operating your SD-171E/SD-174E.
Applications of some of the functions described in this manual are determined by the system you use. Your dealer will
program your radio so that you have the greatest number of functions possible relative to your needs.
Should you have questions regarding the operation of the radio, please consult your Dealer.

3
Specifications
GENERAL
Equipment Type ……………………………………………………… Data radio
Performance Specifications…………………………………………TIA/EIA-603 / ETS 300.113
Band …………………………………………………………………… VHF(SD-171E) / UHF(SD-174E)
Channel Spacings …………………………………………………… 25 kHz, 12.5 kHz programmable
RF Output Power …………………………………………………… 1 watt, 5 watt programmable
Modulation Type …………………………………………………… F2D, F3E
Intermediate Frequency …………………………………………… 45.1 MHz & 455 kHz
Number of Channels ………………………………………………… 16
Frequency Source …………………………………………………… Synthesizer
Operation Rating …………………………………………………… Intermittent
90 : 5 : 5 (Standby: RX: TX)
Power Supply ………………………………………………………… Ext. Power Supply(12 VDC Nominal)
9V - 18.0V DC EXTREME
Temperature Range
Storage ………………………………………………………………… from - 40°C to + 80°C
Operating ……………………………………………………………… from - 30°C to + 60°C
Current Consumption
Standby (Muted) ……………………………………………………… < 65 mA
Transmit 5 Watt RF power ………………………………………… < 2.0 A
Transmit 1 Watt RF power ………………………………………… < 1.0 A
Frequency Bands:
RX TX
VHF : V2 146.000 - 174.000 MHz 146.000 - 174.000 MHz
UHF : U2 450.000 - 490.000 MHz 450.000 - 490.000 MHz
Lock Time ……………………………………………………………… < 10 mS
TX to RX attack time ………………………………………………… < 20 mS (No Power Saving)
RX to TX attack time ………………………………………………… < 20 mS
Dimensions…………………………………………………………… (118mm)H x (63 mm)W x (35 mm)D
Weight ………………………………………………………………… 266.5 grams

4
TRANSMITTER Specification
Carrier Power: ………………………………………………………… Nom. Max. Min.
Hi ………………………………………………………………………5W < 6W > 4.5W
Low ……………………………………………………………………1W < 1.5W > 0.8W
Sustained Transmission …………………………………………… Nominal conditions
Time : 5 10 30 Sec.
Power: >90% >85% >80%
Frequency Error ……………………………………………………… < 0.75 kHz Nominal condition for UHF
±5.0 ppm Extreme condition for UHF
Frequency Deviation:
25 kHz Channel Spacing…………………………………………… Peak ±5.0, Min. ±3.8KHz
12.5 kHz Channel Spacing………………………………………… Peak ±2.5, Min. ±1.9KHz
Audio Frequency Response…………………………………………Within +1/-3dB of 6dB octave
@ 300 Hz to 2.55 kHz for 12.5 kHz C.S.
@ 300 Hz to 3.0 kHz for 25 kHz C.S.
Adjacent Channel Power
25 kHz ………………………………………………………………… < 70 dBc @ Nominal Condition
< 65 dBc @ Extreme Condition
12.5 kHz ……………………………………………………………… < 60 dBc @ Nominal Condition
< 55 dBc @ Extreme Condition
Conducted Spurious Emission …………………………………… < -36 dBm (< 1GHz), -30 dBm (> 1GHz)
Modulation Sensitivity ……………………………………………… 100mV RMS @ 60 % Peak Dev.
Hum & Noise:
25 kHz Channel Spacing …………………………………………… > 40 dB (with no PSOPH)
12.5 kHz Channel Spacing ………………………………………… > 40 dB (with PSOPH)
Modulation Symmetry ……………………………………………… < 10 % Peak Dev @ 1 kHz input
for nominal dev +20dB
Load Stability ………………………………………………………… No osc at ≥10:1 VSWR all phase angles and suitable
antenna
No destroy at ≥20:1 all phase angle
Peak Deviation Range Adjustment @ 1 kHz, Nom. Dev +20dB:
25 kHz Channel Spacing …………………………………………… Min. 3.5, Max. 6.0KHz
12.5 kHz Channel Spacing ………………………………………… Min. 1.5, Max. 4.0KHz

5
RECEIVER Specification
Sensitivity (12dB Sinad) …………………………………………… Standard B.W < -118 dBm, Narrow B.W <-117 dBm
@ Nom. Condition
Standard B.W < -115 dBm, Narrow B.W <-114 dBm
@ Extreme Condition
Amplitude Characteristic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . < ±3 dB
Adjacent Channel Selectivity:
25 kHz Channel Spacing …………………………………………… > 70 dB @ Nom., > 60 dB @ Extreme Condition
12.5 kHz Channel Spacing ………………………………………… > 60 dB @ Nom., > 50 dB @ Extreme Condition
Spurious Response Rejection …………………………………… > 70 dB (100 kHz - 4 GHz)
Image Response ………………………………………………………> 70 dB
IF Response…………………………………………………………… > 70 dB
Others. ………………………………………………………………… > 70 dB
Intermodulation Response Rejection:
±25 kHz/ 50 kHz ……………………………………………………… 70 dB
±50 kHz/ 100 kHz …………………………………………………… 70 dB
Conducted Spurious Emission @ Nominal Conditions:
9 kHz - 1 GHz ………………………………………………………… < -57 dBm
1 GHz - 4 GHz. ………………………………………………………… < -47 dBm
RX Spurious Emissions (Radiated) @ Nominal Conditions
9 kHz - 1 GHz ………………………………………………………… < -57 dBm
1 GHz - 12.75 GHz …………………………………………………… < -47 dBm
AF Distortion. ………………………………………………………… < 3% @ Nom., < 10 % @ Extreme condition
RX Hum & Noise:
25.0 kHz CP …………………………………………………………… < 40 dB No PSOPH
12.5 kHz CP …………………………………………………………… < 40 dB with PSOPH
Receiver Response Time …………………………………………… < 16 mS
Squelch Opening Range: …………………………………………… -113dBm ±2 @ Nom. Condition
Squelch Closing Range (Hysteresis): …………………………… -116dBm ±2 @ Nom. Condition
Squelch Attack Time:
RF Level at Threshold ……………………………………………… < 40 mS
RF Level at Threshold + 20 dB …………………………………… < 30 mS
Squelch Decay Time ………………………………………………… 5 mS Min., 20 mS Max.
Antenna Socket Input Match ……………………………………… > 10 dB Return Loss
L.O. Frequency Temperature Stability …………………………… 1st < 5 ppm, 2nd < 15 ppm from -30° to + 60° C
L.O. Frequency Aging Rate ………………………………………… ±2 ppm/ year

6
Safety Information
WARNING
DO NOT hold the radio in such a manner that the antenna is next to, or touching, exposed parts
of the body while transmitting.
DO NOT allow children to operate transmitter-equipped radio equipment.
CAUTION
DO NOT operate the radio near unshielded electrical blasting caps or in an explosive
atmosphere unless it is a type especially designed and qualified for such use.
NEVER use the radio in an aircraft.
NEVER use the radio near to sensitive medical equipment or in areas where instructed not to do
so, e.g. Petrol filling stations.
When used in a vehicle, do not mount the radio unit on or near the Airbag or Airbag activation
device.
The use of an accessory not recommended or supplied by Maxon may cause damage to
equipment or injury to personnel, and will invalidate warranty.
The outlet must not be obstructed and must be easily accessible at all times.
Never attempt to disassemble, modify or repair the unit unless the work is carried out by a
Maxon approved Dealer.
Incorrect assembly, modification or repair may cause irreparable damage to your unit and will
invalidate warranty.
For service or repair always return your radio to an authorized Maxon Dealer.
I

7
Unpacking information
Remove and carefully inspect the contents of your package(s) for the following items:
Radio
User manual
If any items are missing, please contact the dealer from which you purchased the radios, or contact us at phone number
913-859-9515 or if call within the U.S. toll free at 800-993-9476.
SD-171 / SD-174 Features
•Synthesized Operation with 16 channel capability
•1 / 5 Watt programmable output power
•Programmable 12.5 / 25KHz channel spacing
•Channel scan
•Busy channel lockout
•Tx Time-out timer
•Power Save
•Marked Idle
•Tx Delay
•Data transmission and reception through GMSK modem
•Data transmission and reception through FFSK modem
•Support transmission of global position data

8
Description of radio components
Antenna connector
DB-15 connector
GPS Antenna connector (option)
DIP-S/W
Jumper selector
Exterior View
maxon
1
2
3
Digital Board
RV402
RV403
RV401
SW401
5
4

9
Antenna installation
Fasten the antenna to the radio by turning the antenna cable clockwise into the receptacle on left of radio when looking at
front of radio.
Powering the data radio
Your data radio accepts many sources of DC power to permit more versatile use. This radio operates from 9.0V to 18V DC
and standard voltage for test is 12V DC.

10
SD-170E Series Operation
Channel select / SCAN
Your radio‟s channel can be selected by inner DIP-S/W or serial command inputted from external control system. To change
channel by inner DIP-S/W (), you should open the upper cover and then look for the DIP-S/W() on the digital board of
the bottom cover. Once located, change the DIP-S/W to select wanted channel according to channel dip switch chart.
To use a serial command for channel selection, it should be inputted by external equipment or device (ex. Personal
computer) through Pin 8 of DB-15 connector. See the message format for serial command for full details.
If your radio has been programmed the channel scan, you must enter the scan mode by serial command.
Transmit
The transmission will be made by various inputs such as PTT signal (Pin 3 of DB-15 connector), TX serial command and
Serial data input (Pin 10 of DB-15 connector: This input is only available when a modem option board is installed). TTL level
is used as PTT signal and is active low. If you installed an option modem board, you can use RS-232 level as a PTT signal
instead of TTL level. To maintain transmission, continuous PTT signal input is required. If you use Tx serial command for
transmission, normally, it‟s released by Rx serial command. If RF activity is present; it will not be illuminated if the radio
indicates a “clear”channel. When the channel is “clear”, input the PTT signal or Tx serial command and transmit data or
audio. Remove the PTT signal or input Rx serial command when you have finished transmission.
CAUTION : Operation of the transmitter without a proper antenna installed may
result in permanent damage to the radio.
Receive
When you have finished transmission, remove the PTT signal or input Rx serial command. You will receive data from
another radio or hear another person talking from the connected external speaker.

11
Scan modes
Scanning is a dealer programmable feature that allows you to monitor a number of channels. Your dealer will help you
define a scanning mode and your channel “scan list”
Channel scan
Once the scan list has been established, initiate scan by serial commands. If a conversation is detected on any of the
channels in the scan list, the radio will stop on that channel and you will be able to hear the conversation. At that time, busy
channel data is sent to external equipment or device through serial command. So, you can identify busy channel data as
decoding of received serial command from your radio in the external equipment or device.
Normally, if you try to transmit during scanning, the transmission will be made on the channel that the call was received
during the programmable scan delay time. (The scan delay time is the amount of time the radio will stay on that channel
once activity has ceased. Dealer programming of 4 ~ 7 seconds is typical). The radio will resume scanning once the scan
delay time has expired, and will continue to scan until the serial command for scan stop is inputted by external equipment.
After the scan resumes, if a transmission is made, the radio will transmit on the selected priority channel. This feature is
similar to priority scan TX except for selection of priority channel. You can assign a priority channel by inner dip switch only.
Scan channel delete
To temporarily delete a channel from the scan list, simply input the serial command for scan deletion to the radio while
scanning and stopped on the channel to be deleted. This will temporarily remove that channel from the scan list until the
scan is closed or the radio‟s power is reset.
CTCSS / DCS Scanning
To help to block out unwanted calls to your radio, the SD-170E series can be programmed by your dealer to scan for tones.

12
Channel dip switch chart
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
1
16
2 3 4
5 6 7 8
910 11 12
151413
SW401
CHANNEL SELECT SWITCH
CHANNEL NO.
SWITCH POSITION
Serial command
Serial RX/TX Data Format
(1) Asynchronous Serial Data Transfer
(2) Baud Rate : 4,800 bit/sec
(3) Data Bit : 8bit , Non Parity
(4) Stop Bit : 1bit
(5) MSB first transmission
Each serial command is consist of 3 bytes.
1st byte is command and 2nd is data required by command and 3rd is check sum to decide validity of total contents.
Byte0
ST
1st Byte (Command)
SP
Byte1
ST
2nd Byte (Data)
SP
Byte2
ST
3rd Byte (Check Sum)
SP

13
Data Protocol
Protocol for input Serial command
Protocol of data transmission from external equipment or device (: PC) to radio :
Input serial command
Receive response
Response
External equipment or device Radio
Protocol for output data
Protocol of data transmission from radio to external equipment or device (: PC) :
Receive Data
Receive Data
Output Data
(with command)
External equipment or device Radio
Output Data
(with command)
Serial Commands
Transmit Command & data
Mode
Transmit
Command
(BYTE0)
Transmit data( BYTE1 )
Check sum( BYTE2 )
: Transmit Command + data
1.
Channel Change
0x64
0x?? :Current channel
( 0x64 + Channel )
2.
RTX Mode Send.
0x61
R(0x72) : Rx mode
T(0x74) : TX mode
( 0x61+0x72 )
( 0x61+ 0x74 )
3.
Scan
Mode
From PC
To Radio
0x62
F(0x46) : Scan Stop
S(0x73) : Scan Start
O(0x4F) : Scan Delete
( 0x62+ 0x46 )
( 0x62+ 0x73 )
( 0x62+ 0x4F )

14
From Radio
To Pc
0x66
0x00 : 1 Channel
0x01 : 2 Channel
0x02 : 3 Channel
0x0f : 16 Channel
0x66 + 0x00
0x66 + 0x01
*Only for Unmute Channel,
Correct Call Channel
Error
Message
0x65
It occurs when Scan Delete command comes except
for Busy/Correct Call
It occurs when PTT key is pushed except for
Busy/Correct Call.
It occurrs when channel change command exists
during Scanning.
4.
GPS
mode
Control of
GPS Power
0x6a
0x00 : GPS Power Off
0x01 : GPS Power On
( 0x6a + 0x00 )
( 0x6a + 0x01 )
Control of
GPS Data
0x63
0x00 : GPS Data Disable
0x01 : Release GPS Data
to DB-15
0x02 : Release GPS Data
to Modem
( 0x63 + 0x00 )
( 0x63 + 0x01 )
( 0x63 + 0x02 )
5.
Modem test mode
0x75
0x78 : Enable test data
0x79 : Disable test data
( 0x75 + 0x78 )
( 0x75 + 0x79 )
6.
Modem
alignment
mode
GMSK
0x7a
0x00 : Disable
0x01 : Enable
( 0x7a + 0x00 )
( 0x7a + 0x01 )
FFSK
0x7c
0x00 : Disable
0x01 : Enable Mark data
( 0x7c + 0x00 )
( 0x7c + 0x01 )
0x7e
0x00 : Disable
0x01 : Enable Space data
( 0x7e + 0x00 )
( 0x7e + 0x01 )
7
SQLC Data
RSSI
Data
0x41
0x00 : None
( 0x41 + 0x00 )
Squelch
UP
0x42
0x00: None
( 0x42 + 0x00 )
Squelch
Down
0x43
0x00: None
( 0x43 + 0x00 )
Receive Command & data
Mode
Transmit
Command
(BYTE0)
Transmit data ( BYTE1 )
Check sum( BYTE2 )
: Transmit Command + data
1
Process Complete
Commands
0xaa
ACK
0x55
NACK
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 user receives Nack data, user should send command again.
example) If user changes from 1st Channel to 2nd Channel,

15
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
changes to 2nd channel. If not, Radio would send Nack data.
Audible alert tones
Your SD-170E series data radio has a sophisticated microprocessor control which provides a range of audible tone. If you
connect the Speaker filtered OUT (Pin 9 of DB-15 connector) to an external speaker, you can hear audible tones at the
following conditions:
•Attempt to transmit on a channel that is already in use when busy channel lockout has been programmed into the radio
•Transmission time has exceeded time-out timer programmed length
•When the other group or people finished transmission using repeater
See the status audible alert tones chart for full details.
STATUS
DESCRIPTION
AUDIBLE TONE
WARNING
Busy Channel lockout
Single Beep Tone ( 800Hz )
Before 5S T-O-T
Single Beep Tone ( 800Hz )
Transmit Hang on time
Single Beep Tone ( 800Hz )
ERROR
PLL Unlock Error
Single Beep Tone ( 640Hz )

16
DB 15 PIN descriptions with input/output level
D-Type
Pin No.
Function
Description
Signal Type
Input/
Output
1
Data modulation IN
(Tx Mod)
Signal is directly injected to MOD through data
low pass filter without pre-emphasis.
Analog signal
1KHz audio at 60%
peak system deviation
input level =
100 to 120mVrms
I/P
2
Data unfiltered OUT
(RX disc)
Discriminator audio from the SD-170E. This is
the unprocessed AF signal prior to tone
filtering and de-emphasis.
Analog signal
1KHz audio at 60%
peak system deviation
produces
200 to 300mVrms
O/P
3
PTT In
(Tx Key)
Signal from the „external device‟to key the
SD-170 transmitter.
This line has an internal pull up resistor to +5V.
Pulling the line to 0V turns on the transmitter.
Note : If you installed option modem board,
you can select RS-232 signal level by
Jumper (CON407, ) on the digital board.
TTL level
0V = Tx
o/c = Rx
RS-232 level (option)
+12V = Tx
-12V = Rx
I/P
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, ) 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 @ 8Ω
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

17
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
DGPS data input
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 building a cable to interface with the SD-170E, the ground connection is made by grounding the outer shell of the
DB-15 connector. Make sure the securing screws are tight on the connector when installing it to the unit

18
Modem option for data communication
DESCRIPTION
The ACC-513E and ACC-514E are internal option-modems, which are applied to the SD-170E series to increase capability
for data applications. The goal of an internal modem is to improve the efficiency for data transmission and provide
maximum flexibility for user applications. The most obvious method of increasing the data efficiency is to maximize the data
signaling speed in the limited channel bandwidth. But, FSK, called direct FM modulation, has a very wide transmission
bandwidth requirement. To solve this problem a GMSK (Gaussian Filtered Minimum Shift Keying) internal option-board can
be used. Generally data has a wider bandwidth than audio. So, direct application of data is not matched with an audio
system and its application. For instance, if sub-audio (Tone) SQ system applied to a data application, its frequency conflicts
with that of sub-audio. Moreover, the inputted data is filtered by the audio filter circuit resulting in broken data transmission.
To overcome these problems and provide maximum flexibility, an FFSK (Fast Frequency Shift Keying) internal option-board
can be used.
COMMUNICATION BETWEEN DTE AND OPTION-BOARD
Our internal modem options consist of Slave MCU, Modem IC, and extra circuitry. These option-boards directly
communicate with DTE (Data Terminal Equipment) to send and receive meaningful data through the DB-15 connector on
the digital board of the SD-170E. These modems are designed to accept RS232 serial data format and are also capable of
high speed wireless data-transmission between two or more devices. More detailed information for the modem option
boards is given in the technical manual for the ACC-513E/514E. Your dealer will help you define a TX On/Off delay time,
RX On delay time, Baud Rate, Modem Enabled, Modem Baud Rate, Data flow control, and Test Mode.
Table for modem speed
Channel Space
DTE Baud Rate
Modem Baud Rate
Narrow (12.5KHz)
1200
1200
2400
2400
Standard (25KHz)
1200
1200
2400
2400
4800
4800
Table 1. Available Baud rate for FFSK modem

19
Channel Space
DTE Baud Rate
Modem Baud Rate
Narrow (12.5KHz)
4800
4800
Standard (25KHz)
4800
4800
9600
9600
Table 2. Available Baud rate for GMSK modem
Transmission GPS Data through Modem
The SD-170E supports GPS data handling. That may help your implementation for a system related to GPS. If it is not
enough for your application, received position data from the GPS module placed in an SD-170E can be reprocessed by
your own application. The ACC-515E is a GPS module for the SD-170E, which releases 11 different output data according
to the NMEA-0183 format, which can be selected by you, the available data should be processed by your application.
Received data from the ACC-515E will be released via the DB-15 connector of the SD-170E and/or transmitted to another
system through an installed modem. More detailed information for the GPS option board is given in the technical manual for
the ACC-515E.

20
Option board pin-out chart
FFSK Modem Option board
Connector
No.
Pin
No.
Function
Description
Input/
Output
Connector 1
1
VCC
6V to 12V Power Input
I/P
2
GND
Ground
3
PTT
Signal from the digital board to transmit data key the SD-
170 transmitter
I/P
4
TXD_EN
It ensures that the radio has stabilized in transmission
before the data is processed for modulation.
I/P
5
TX_END
To finish transmission, it indicates memory buffer of Master
MCU of digital board is empty.
O/P
6
MUTE
(Busy)
Logic level input from digital board to indicate whether a
carrier is present or not
I/P
7
MODEM_EN
Modem Enable input
I/P
8
POWER_SAVE
Power save input for modem board.
I/P
9
CMD_EN
It indicates that command for Modem programming is
effective.
I/P
10
CMD_IN/OUT
Data Input and Output for Modem programming.
I/P,
O/P
11
CMD_CLK
Clock Input for Modem programming.
I/P
12
MODEM_SEL
It Indicates modem type to Master MCU for programming.
O/P
13
RX_IN
The FFSK/MSK signal input for the receiver of modem IC.
I/P
14
TX_OUT
The FFSK/MSK signal output when the transmitter is
enabled.
O/P
Connector 2
1
Serial_IN
The Serial data to be transmitted is input to this pin.
I/P
2
Serial_OUT
The recovered asynchronous serial data output from the
receiver.
O/P
3
Busy
To eliminate data loss according to buffer overrun of slave
MCU‟s memory, it indicates buffer status.
O/P
4
Carrier_Detect
Handshake signal for RTS control mode. It indicates
whether Slave MCU of modem has decoded data or not.
O/P
5
PTT_IN
Handshake signal for RTS control mode. It requests data
transmission to Slave MCU of modem.
I/P
6
PROGRAM
It‟s reserved input for firmware upgrade.
I/P