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7.2. Dumb Mode
To give compatibility with existent radio, this mode is provided. In this mode, Standard
Terminal Emulation programs, such as Procomm, can be used for communication
between the SD-160 radios but the PTT/RTS line has to be controlled, manually, from
another source.
NOTE : The Dumb mode will not transmit simply by sending it
’
s data.
This operating mode uses 6wire cable like in hardware flow control and jumper position
of CON407. If the DTE has data to transmit, the DTE applies a 2.5V high to the
PTT/RTS line on pin 4 of the DB-15 connector, which will cause the radio disable the
receive circuits and switch the transmitter on, and then release data to radio. This size
of data to be released should be limited under size of the buffer memory of the slave
MCU. After all assigned data is transmitted, the DTE returns RTS signal below -2.5V to
complete the transmission. In other words, the RTS line is used like a conventional PTT
line in this mode.
DTE
Slave MCU
Modem IC
RF
TXD
Modem CTRL
Modem DATA
Modulated
Data
Received
Data
RXD
GND
<RS232>
Control Line
<Modem Option Board>
Master MCU
Control Line
<SD160 Main Digital Board>
<SD160 RF Board>
Buffer 1
Buffer 2
RTS
CTS
Figure 7.6. Data and Control signal flow in Dumb mode
7.3. Test Mode
This operating mode is simple transmission test. The radio transmits programmed data,
"
Testing Maxon Modem ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", which
exists in the internal memory of the modem. Refer to ACC 916 user manual for detailed
instruction.
