Midland SD-250, Руководство пользователя, Страница: 5 / 20

Rev. 0B
4
Description of modem
The SD250 is a network free, point to point RF data module that offers great
flexibility in varied applications where wireless data or voice communication is
needed.
It can be used as a transparent radio, with no internal modem fitted, to allow
users to facilitate the use of their own modem and protocol. The correct signal
levels need to be used with the use of separate control lines, see the pin out
table below.
The SD250 can also be fitted with below a few different modems
• Bell 202 / V.23 modem (1200 baud rate)
• FFSK modem (4800 baud rate)
• GMSK modem (9600 baud rate)
The internal modem allows communication with a pc using RS 232 for the data
and control lines. For further details, please refer to the modem manual.
SD250 has standard radio features available which are associated with a private
radio. This includes CTCSS and DCS, software controlled squelch, time out timer
options and busy channel lockout as listed below (not all available with option
modem fitted). There is a microphone input and speaker output to allow speech
to be transmitted and received.