Service manual

Service Manual SD170E Series
Page 28 of 44
Modem Options
Modem Option for data communication
ACC-513E and ACC-514E are new kinds of internal option-modems, which are applied to SD-
170E series to increase capability for data application. The goal of internal modem is to improve
the efficiency for data transmission and provide maximum flexibility for user application. In former
case, the most obvious method of increasing the efficiency is to maximize the data signaling
speed in the limited channel bandwidth. But, FSK, called direct FM modulation, has very wide
transmission bandwidth requirement. To solve this problem, MaxonCIC supplies GMSK
(Gaussian Filtered Minimum Shift Keying) internal option-board. In latter case, to improve quality
of service, some of service provider (or user) wants to apply new radio to their existing system
without additional investment to establish new system even if it‟s audio system. But, data
application can‟t be directly applied in audio system because of its spectra characteristic.
Generally, spectra of data have wider bandwidth than audio. So, direct application of data is not
matched with audio system and its application. For instance, if sub-audio(Tone) SQ system is
applied to data application, its frequency spectra conflicts with that of sub-audio. Moreover, if
inputted data is filtered by audio filter circuit to avoid this problem, some of that will be broken.
Therefore, to get over these problems and provide maximum flexibility, Maxon prepares FFSK
(Fast Frequency Shift Keying) internal option-board.
Our internal modem option boards consist of 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 on digital board of SD-170E. These are designed to
accept RS232 serial data format and also capable of high speed wireless data-transmission
between two or more devices. More detail information for modem option boards is given in
technical manual for ACC-513/514. Moreover, 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
Available Baud rate for FFSK modem
Channel Space
DTE Baud Rate
Modem Baud Rate
Narrow (12.5KHz)
4800
4800
Standard (25KHz)
4800
4800
9600
9600
Available Baud rate for GMSK modem
GPS option board
As one of the methods to satisfy various requests for user application, SD-170E supports GPS
data handling. That may help your implementation for system related to GPS. Nevertheless, if it‟s
not enough for each your application, received position data from GPS module placed in SD170E
can be reprocessed by your own application. ACC-515E is GPS module for SD170E which
releases some of 11 different output data according to NMEA-0183 format. Moreover, it can be
also selected by user, but it should be processed by user‟s application. Received data from ACC-
515E will be released via DB-15 connector of SD-170E or/and transmitted to other system
through installed modem. More detailed information for GPS option board is given in technical
manual for ACC-515E.