Maxon ACC-513E User manual

ACC-513E/ACC-514E
(GMSK/FFSK Modem, SD-170E Series)
Technical Manual
Rev 1.0
July 17, 2013
Maxon Telecom Co., Ltd

Contents
1. Introduction...............................................................................4
2. Technical Specification............................................................. 5
2.1. Specification for ACC-513E............................................................5
2.2. Specification for ACC-514E............................................................6
3. Installation of ACC-513E/ACC-514E....................................... 7
4. System Application.................................................................. 10
4.1. Fixed applications...........................................................................10
4.2. Mobile Applications........................................................................12
5. Operation.................................................................................. 13
5.1. Serial interface ...............................................................................13
5.2. Configuring the SD-170E ..............................................................16
6. Understanding Modem Option................................................. 19
6.1. Modem Select ..................................................................................19
6.2. System Option 1.............................................................................. 20
6.3. System Option 2.............................................................................. 21
6.4. System Option 3.............................................................................. 22
7. Modem Operation Explained.................................................... 23
7.1. Auto Mode....................................................................................... 23
7.1.1. Flow Control ................................................................................................. 23
7.1.2. Software flow control.................................................................................... 24
7.1.3. Hardware flow control .................................................................................. 24
7.1.4. None (No flow control)................................................................................. 26
7.2. Dumb Mode.........................................................................................27
7.3. Test Mode ........................................................................................... 27
7.4. Operating Diagram ............................................................................ 28

8. Example of Operation Test..................................................... 30
8.1. Example of using Hyper Terminal.................................................. 30
9. Pin-out chart for ACC-513E/514E.......................................... 40
9.1. Pin-out for ACC-513E ..................................................................40
9.2. Pin-out for ACC-514E ..................................................................41
10. Product version information.................................................. 42
10.1. Version information.........................................................................42

1. Introduction

The ACC-513E and ACC-514E are optional accessories that can be installed into the SD-170E
series radios to improve capability for data applications. The goal of an internal modem is
to improve the efficiency for data transmission and provide maximum flexibility for user
application. 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 a data application cannot be directly applied in an audio system (Voice)
because of its spectra characteristic. The spectra of data has a wider bandwidth
than audio. So, a direct application of data is not matched with audio system (Voice) and
its application. For instance, if a sub-audio(Tone) SQ system is applied to a data
application, its data frequency spectra will conflict with that of sub-audio tones.
Moreover, the inputted data is filtered by the audio filter resulting in a broken data
transmission. To overcome these problems and provide maximum flexibility, an
FFSK(Fast Frequency Shift Keying) internal option-board modem can be used.
Our internal modem option boards consist of a Slave MCU, Modem IC, and extra
circuitry. These option-boards directly communicate with DTE (Data Terminal
Equipment) to send and receive the meaningful data through the DB-15 connector to
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. To cope with various applications the SD-170E can be controlled by
automatically or manually. In automatic control the SD-170E will transmit simply by
automatically sending data. The data to be transmitted is automatically stored while the
transmitter is turned on. Before the data is transmitted, a preamble sequence is
transmitted to synchronize the receiving modem. The data is placed in data blocks
(packets) with header and end data information added. In manual control, when the SD-
160 receives data from DTE, the data communication process is almost similar to the
a

uto mode except that transmission is controlled by a control signal such as PTT or RTS.

2. Technical Specification
2.1. Specification for ACC-513E
Modulation type: Modified GMSK
Maximum RF Baud rate: 4800 (12.5 KHz) channel spacing and 9600 (25 KHz) channel
spacing (Programmable, see below table)
Data Sensitivity: below –113dBm for 1 in 100 error rate
Method for elimination of DC offset: Data scrambling
Data input/output: RS232
RS232 Baud input rate: follow the RF Baud rate (see below table)
Number of Data Bit: 8 bits
Parity: None
Number of Stop Bit: 1 bit
Data flow control: None, Software (Xon/Xoff),
Hardware (RTS/CTS) (Programmable)
Tx forcing mode: Configures the modem to transmit regardless of squelch state
Data Block (Packet) size: Programmable from 16bytes to
8192bytes by multiple of 16bytes increments. To provide
maximum flexibility, the packet doesn’t include additional bits
for error detection and correction. We recommend that the
users add their own methods for error detection/correction.
Table 2.1. Available Baud rate for GMSK modem
2.2. Specification for ACC-514E

Modulation type: FFSK
Maximum RF Baud rate: 2400 (12.5 KHz) channel spacing and 4800 (25 KHz) channel
spacing (Programmable, see below table)
Data Sensitivity: below –110dBm for 1 in 100 error rate
Mark /Space tone freq. (for each available RF Baud rate):
1200Hz (M) / 1800Hz (S) at 1200bps
1200Hz (M) / 2400Hz (S) at 2400bps
2400Hz (M) / 4800Hz (S) at 4800bps
Data input/output: RS232
RS232 Baud input rate: follow the RF Baud rate (see below table)
Number of Data Bit: 8 bits
Parity: None
Number of Stop Bit: 1 bit
Data flow control: None, Software (Xon/Xoff),
Hardware (RTS/CTS) (Programmable)
Tx forcing mode: Configures the modem to transmit regardless of squelch state
Data Block (Packet) size: Programmable from 16bytes to 8192bytes by multiple of 16
bytes increments. To provide maximum flexibility, packet
doesn’t include additional bits for error detection and correction.
We recommend that the users add their own methods for
error detection/correction.
Table 2.2. Available Baud rate for FFSK modem

3. Installation of ACC-513E/514E
This section explains step-by-step how to disassemble the SD_170E radio, install the ACC-
513E/514E, and reassemble the radio.
Important
Before disassembling and reassembling the radio, wear a conduction wrist strap to
prevent any components on its main board from being damaged by electrostatic discharge.
Opening the Upper Cover :
1. Unscrew the four mounting screws located on the top cover of the radio.
2. Remove the lid.
Installation of ACC-513E/514E:
1. Install the modem by aligning both sets of header pins into the corresponding sockets
located on the digital board of the radio. Press firmly into place.
Closing the Upper Cover :
1. Align the upper cover with the bottom cover.
2. Close the upper cover. Install and tighten the 4 screws.

4. System Application
The SD-170E is a flexible data radio transceiver intended for a wide variety of
applications. The basic radio data applications may be divided into several categories,
examples of these are:
•Point to point telemetry (Data logging system)
•Tele-command and tele-control to / from outstations or machinery
•Automatic irrigation system
•Job allocation and status reporting
•Automatic location reporting / polling
Typical function specific systems may include the following:
4.1. Fixed applications
1. Control point to multiple outstation tele-control. Used for control and exception
reporting in water pumping stations and other similar situations. (See Figure 4.1.)
Figure 4.1. Tele-control Application

2. Point to point telemetry using FFSK or GMSK modulation with RS232 control via a
micro-controller. User applications for this may include remote control data links
such as control of a remote paging transmitter or single direction status reporting or
data flow (see Figure 4.2.) from a gas pipeline monitoring station.
Figure 4.2. Telemetry Application
3. Multiple remote sites to control irrigation system (see Figure 4.3.)
Figure 4.3. Irrigation equipment control Application

4.2. Mobile Applications
4. Local area mobile system for job allocation and status reporting to and from taxis.
(see Figure 4.4).
Figure 4.4. Job allocation and status reporting Application
5. Marine data communications for ports / harbors and inland waters allowing GPS
navigation information to be relayed from vehicle or vessel to a control point.
Figure 4.5. Vehicle / Vessel Data Application

5. Operation
By installing the ACC-513E or ACC-514E, the SD-170E can be used as a radio data-generating
device utilizing GMSK or FFSK type modulation. There is a micro-controller to control your
overall application, including the radio to handle data to transmit or receive. The radio is
controlled through the DB-15 connector and interfaces with a DTE by an interface cable.
In operation, the radio is placed into the transmit condition by receiving data from DTE.
If the radio receives data, the slave MCU of the ACC-513E/514E saves that data in its
memory and automatically creates a PTT signal at the same time to get the RF stage to
prepare for transmission. To avoid data loss in transition time of the RF stage, it is
important that there is a delay between activating the PTT signal and applying the data
to the RF stage. In these processes, there are many tunable parameters, which will be
explained in the next section, to provide maximum performance for user application.
This section describes the basic connection for data transmission or radio control and
then explains important parameters for data transmission.
5.1. Serial interface
In some systems, where data is required to be inputted to a SCADA system or simple
PC logger, the most useful receiver output will be the RS-232 serial stream. Any
system using serial data output will also require DTE(Data Terminal Equipment) such as
a PC, or workstation driver package, or PDA, to display the data and upload it into a
host process. So, To interface with these external equipment, the SD-170E contains a 15
pins D-sub female connector. The serial interface is configured as DCE with the pin out
shown in the table below.
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, r) on
TTL level
0V = Tx
o/c = Rx
RS-232 level (option)
+12V = Tx
I/P

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 @ 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
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.

The serial protocol supported by the ACC-513E/514E is fixed at 1 start bit, 8 data bits, 1
stop bit and no parity. Flow control can be selected as either hardware (RTS/CTS),
software (XON/XOFF) and none. The serial baud rate is also user configurable and
supports the following rates: 1200, 2400, 4800, 9600bps.
Depending on the user application, the SD-170E can be connected with one or two serial
communication port to control the unit through the interface cable. Normally the radio’s DB-15
connector is connected with one communication port of the control unit to transmit or receive data.
However, if the application requires additional control such as channel change, an additional
communication port is needed to control the radio through serial command.
Figure 5.1. shows an interface cable for data communication and its inner connection. In
the connection, red lines, pins 3, 6 and 12 on the SD-170E are the minimum required
connection to transmit and receive RS-232 data, and blue lines, pins 4,10, and 11 on the
SD-170E are additional connection for handshaking. In Figure 5.2., additional connection
for radio control is added, which needs RS-232 driver to connect the RS-232 serial
port because the radio control signal uses a TTL level to provide compatibility with
former system. Detailed interface information and its use are given in next section.
Figure 5.1. Interface cable for data communication and its inner connection.

Figure 5.2. Interface cable for data communication and radio control
5.2. Configuring the SD-170E
In case of mobitex application, which is an international and open standard for dedicated
wireless data for professional users, all timing is decided by recommendation of
network system. But, this radio does not use a specific network system. For this reason,
timing parameters will be tuned by the user to fit their own system realization.
5.2.1. Data Transmission (Tx)
If the SD-170E receives data from a DTE, the Master MCU of the SD-170E will get RF
stage to prepare for a transmission. In this case, proper timing is required to stabilize
the RF stage (ex. PLL lock time, Power-up time, and etc.). To prevent data loss,
inputted data will be saved in the internal memory, called a buffer, in the slave MCU of
the modem option board by the completion of the RF stabilization. The model contains
tunable value for this period of time, which the user can adjust these timings into their
system within the limited range. Especially, “Tx On delay” and “Tx Off delay” which are
important timing parameters in the transmitter. (see Figure 5.3.)
Tx On delay : The period of time for transmitter’s stabilization before the data is
processed for modulation.

Tx OFF delay : The period of time for avoidance for cutting off the tail end of the
data bit stream.
Figure 5.3. Timing parameters in data transmission
5.2.2. Data Reception (Rx)
If the Slave MCU receives a Rx_ready signal from the Master MCU, the Slave MCU on
the modem option board will get the Modem IC to prepare to receive data, at the same
time, the Master MCU releases a Busy detecting signal through the DB-15 Connector.
Before receiving data, the Modem IC or receiver should be synchronized by a
transmitted preamble sequence. To prevent synchronization by unwanted signal, a time
delay, called “Rx On Delay”, is needed between squelch open (the point of busy
detection) and data signaling path to Modem (see Figure 5.3.). If insufficient preamble
code is released from another radio, data loss will occur by missing synchronization. So,
a minimum period of time is required for synchronization, this is given by modem IC
specification and you can adjust this value within the limited range. Additional detailed
parameters for ACC-513E/514E will be given in the next section.

6. Understanding Modem Option
In this section, explanation of modem options in ACC-916E, PC Programmer is given. The
modem option consists of four groups, MODEM SELECT, SYSTEM OPTION 1,2 and 3.
In MODEM SELECT, the type of modem and modem speed for channel space are
selectable and in SYSTEM OPTION1, transmission mode of radio and functions of
forcing TX and initializing Hyper Terminal are chosen. In SYSTEM OPTION 2, options
for R/TX data format and its processing is selectable. In SYSTEM OPTION3, On/OFF
delay time for R/TX is inputted.

6.1. Modem Select
a. GMSK/FFSK
You can select modem type (GMSK/FFSK). Mark on check box.
b. Modem Enable/Disable
If you want to use modem, click on <Modem Enable> Button.
c. Modem Baud Rate
Table 6.1. Available Modem Baud Rate
In above cases, Modem speed is selectable.
6.2. System Option 1
a. Auto Mode
The radio will be automatically controlled by existence of inputted data from a DTE.
There is no need for the user to be concerned with operation of the radio. The
SD-170E will transmit simply by sending data.
b. Dumb Mode
The Radio should be controlled by user application, manually. For instance, to
transmit data, you should input PTT(RTS) signal besides assigned data. Moreover,
in control of the radio, exact timing should be defined by you. This mode is only
provided to give compatibility with existing radios.

c. TX Forcing Mode
During RX mode, when the Radio receives data from the DTE, if TX Forcing Mode
Option is enable, the radio will transmit data. If disabled, the radio will not.
d. Initializing Data for HT (Hyper Terminal)
This is a strongly recommended option when using Hyper Terminal. In addition, you
can check the version of the modem.
6.3. System Option 2
a. Base Block Size 1
This option is about the data size to be transmitted at one time. If data flow control
is selected in Auto mode, radio will try handshaking after a transmission of
assigned data. you can select the Base Block Size1 according to communication
conditions. Proper value is maximum data size to complete successful transmission
without any error. Usually, under 128 byte (Default) is recommended. Detailed
information is given in Section 7.4.
b. Preamble Data Size
This size of bit is for synchronization of the modem. At least 32 bits (Default) is
recommended. Detailed information is given in Section 7.4.
c. Wait for Busy Time
After the radio transmits established data, the radio waits for a response signal. If
there is no response signal, after this specified time elapses, next data will be
transmitted, next data will be transmitted on receiving response signal. Normally,
1000ms (Default) is recommended.
d. Flow Control
There are three methods to control data. Under Auto Mode, you can select
Xon/Xoff, RTS/CTS or NONE but in Dumb Mode, this is fixed to NONE. Detailed
information is given in Section 7.1.
Software : Flow Control is controlled by Xon/Xoff code.
Hardware : Flow Control is controlled by RTS/CTS of RS-232
None : Radio does not use any Flow Control.
e. Tx Delay Time 1
In Auto Mode, to prevent frequent transmission due to irregular data input, this
option allows for the radio to enter transmission mode after an assigned time. For
your reference, frequent transmission spends too much time for its preparation

such as PLL lock, Power-Up, stabilizing Power, and etc. So, it will degrade overall
system performance. Usually, the SD-170E series uses at least 20ms (Default).
f. Tx Delay Time 2
This is the required time to detect tone, and is only available for the FFSK Modem
and channel with Tone (CTCSS/DCS). In case of SD-170E series, 250ms (Default) is
recommended.
g. Number of Allowable Errors for Start Bit
This option prevents the radio from receiving invalid data by an external
disturbance. Consequently, the more unwanted signal the radio receives, the less
selectable value you may select.
6.4. System Option 3
a. Tx Off Delay
If all assigned data is transmitted, after the transmission the Radio keeps the TX
status during this period of time, TX stops. Normally, in case of the SD-170E series,
0ms (Default) is recommended. Detailed information is given in Section 5.2.
b. Tx On Delay
Radio transmits data after elapsing this period of time since TX starts. In case of
the SD-170E series, 20ms (Default) is recommended. Detailed information is given in
Section 5.2.
c. Rx On Delay
The radio enters RX status after elapsing this period of time since receiving the
carrier. In case of the SD-170E series, 16ms (Default) is recommended. Detailed
information is given in Section 5.2.
7. Modem Operation Explained
This section explains each operating mode and details the modem serial pin connections.
There are two types of modes, Auto and Dumb mode. In Auto mode, the radio is
automatically controlled by existence of inputted data from a DTE. To avoid data
overflow by limitation of the buffer memory due to continuous input, serial port data
flow is controlled by the radio in communication with a DTE. In Dumb mode your
application should control all these processes such as Tx preparation for the RF stage

and handshaking. Basic pin connection types that can be used are a three, RXD, TXD
and GND or five, RXD, TXD, GND, RTS and CTS signal line. RS232 is used according to
flow control. In addition, the CD signal line can be utilized for your application.
7.1. Auto Mode
This mode is “intelligent” and removes the need for the user to understand how the
radio system is used. The data to be transmitted is automatically stored while the
transmitter is turned on and transmitted after finishing preparation for transmission. For
this reason, there is nothing to do to as a user except inputting data to the radio. Even
though there is a timing difference between inputted data from the DTE and transmitted
data from the radio, applying flow control for this mode ensures that the transmit buffer
does not overflow. This operating mode supports software, hardware and none flow
control, and pin connections are changed according to the type of flow control used.
The detailed instruction for flow control is the following.
7.1.1. Flow Control
The buffers in the radio modem and its flow control function permit serial
communications even if the speed differs between the computer (DTE) and the modem
DCE or between the radio modems (modem ports). If there is a speed difference
between the serial port and modem port (DTE speed and radio throughput), the buffers
in the radio modem may become full periodically. Therefore communications speed is
controlled so that data transmission and reception is temporarily halted before the data
exceeds the buffer capacity, and that transmission is resumed when the receiving buffers have
room. This is the flow control function. The radio has two kinds of flow control:
•Software flow control
•Hardware flow control