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5. OPERATION
Caution:
Turn the POWER switch OFF before making connections.
With R-5000, unplug the AC plug (or DC plug).
5-1. Precautions for Computer-
Connected Operation
When connecting the transceiver with a computer, check
the following points.
1. Are the connections correct?
The
transceiver
output
should
be connected
to the
computer input and the transceiver input to the com-
puter output.
Example:
Transceiver's receive data — Computer's receive data
Transceiver's RTS — Computer's CTS
2. Is the computer's transmisson rate 4800 BPS (bits per
second)?
3. Is the computer's bit configuration correct?
1 start bit, 8 character bits, 2 stop bits, no parity.
5-2. Control Operation
Most computers handle data in the form of "bits", and "by-
tes".
A bit is the smallest piece of information that the
computer can handle. A byte is composed of 8 bits. This
is the most convenient form for most computer data. This
data may be sent in the form of either serial or parallel data
strings. The parallel mode is faster, but more complicated,
while the serial form is slower it requires less complicated
equipment, and therefore is less expensive.
Serial transmission of data occurs over a single line using
time-division methods. This use of a single line also offers
the advantage of reducing the number of errors due to line
noise.
For control of the transceiver via the computer only three
lines are theoretically required: transmit data ( TXD ), re-
ceive data (RXD), and ground (GND).
From a practical
standpoint it is also necessary to incorporate some means
of controlling when
this data transfer will occur.
The
transceiver has the buffer for reception and the computer
may have also that. Then the RTS and the CTS lines will
control each data transfer never overflow those buffers.
The IF-232C is used in conjunction to provide voltage con-
version. RS-232C deals in voltages above and below TTL
levels, and must be converted to prevent damage to the
transceiver.
This interface/conversion
is handled by the
IF-232C.
The actual command sequence would be similar to those
described below:
For example, the radio is placed into the transmit mode
whenever the character string "TX" is sent from the com-
puter. The character string "TX" is called
a command.
It
tells the transceiver to do something.
There are 23 differ-
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