Mobile Expertise Ltd D350V2 Benutzerhandbuch
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15
Channel selection
Channels are selected by the use of internal switches and
can be set as shown below. The bottom 4 screws will
need to be removed to gain access to the switches, care
must be taken to avoid any damage which could invalidate
the warranty.The channel can also be changed by a serial
command inputted from the external control system.
can be set as shown below. The bottom 4 screws will
need to be removed to gain access to the switches, care
must be taken to avoid any damage which could invalidate
the warranty.The channel can also be changed by a serial
command inputted from the external control system.
Figure: Setting of channel selector switch for each channel
By altering link options, channel change can also be
implemented using TTL levels on pins 11,12,13 & 15 of
DB15 way assuming these pins are not in use and default
conditions are met. Refer to Application Notes on the
Mobile Expertise web site.
implemented using TTL levels on pins 11,12,13 & 15 of
DB15 way assuming these pins are not in use and default
conditions are met. Refer to Application Notes on the
Mobile Expertise web site.
Operation
Transmit/receive operation
The me-d200/d350 can be put into transmit by different
methods. When used as a “dumb” radio, the PTT line is
pulled low (pin 3 of DB15). The Tx serial command will
also put the radio into transmit (pin 8 of DB15), until the Rx
serial command is received.
methods. When used as a “dumb” radio, the PTT line is
pulled low (pin 3 of DB15). The Tx serial command will
also put the radio into transmit (pin 8 of DB15), until the Rx
serial command is received.
Where an internal module is fi tted the PTT/Busy links are
changed to RS232 (see module manual). The GMSK and
FFSK can in addition operate automatically by going into
“TX” on receipt of data on pin 10 of DB15.
changed to RS232 (see module manual). The GMSK and
FFSK can in addition operate automatically by going into
“TX” on receipt of data on pin 10 of DB15.
Serial commands
The modem can be controlled by using the serial command
(pin 8) data in, sending commands to the radio such as
PTT or change channel
(pin 8) data in, sending commands to the radio such as
PTT or change channel
The format for these commands (asynchronous) are:
Baud rate: 4800 bit/sec
Data: 8 bit,
Parity: Non parity
Stop Bit (SP): 1 bit
MSB fi rst transmission
Data: 8 bit,
Parity: Non parity
Stop Bit (SP): 1 bit
MSB fi rst transmission
Each serial command consists of 3 bytes. The fi rst byte is
the command (CMD), the second is data (DATA) required
by the command and the third is the check sum (CS) to
validate contents
the command (CMD), the second is data (DATA) required
by the command and the third is the check sum (CS) to
validate contents
TX Command format:
CMD
DATA
CS
1st byte
2nd byte
3rd byte
N.B. Check Sum = 1st byte + 2nd byte. CS = CMD + DATA
Response format:
CMD
DATA1
DATA2
...
DATAn
The response CMD is in the form of:
ACK, acknowledge, Hex: 0xAA; (then data if any)
NACK, no acknowledge (error in command) Hex: 0x55
NOK, not okay (cannot carry out command) Hex: 0x65
NACK, no acknowledge (error in command) Hex: 0x55
NOK, not okay (cannot carry out command) Hex: 0x65
If command is not recognised, repeated or already in
requested or wrong state e.g channel change in TX there is
no response from the radio.
requested or wrong state e.g channel change in TX there is
no response from the radio.
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SW401
CHANNEL NO.
SWITCH POSITION
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