Appendix D: Com Connector; Hardware Description; Control Operation; Commands Ou - Kenwood TS-870S Instruction Manual

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APPENDIX D: COM CONNECTOR
PROTOCOL
HARDWARE DESCRIPTION
The TS-870S uses a full-duplex, asynchronous, serial
interface for communicating through the male 9-pin
RS-232C COM connector. Bytes are constructed with
1 start bit, 8 data bits, and 1 stop bit (4800 bps can be
configured for 1 or 2 stop bits). No parity is used. The
pinout and the pin functions of the COM connector are
as shown below:
COM CONNECTOR
com | COM Pin Name Function
:
1 NC | = | —
2 RXD | Transmit data | Output |
3 TXD | Receive data Input
4 | NC
=
ce
5 | GND |__ Signal ground |
6 NC _ | —
7 RTS | Receive enable | Input
8 CTS | Transmit enable | Output
9 | NC ie
RXD: The transmit data is the serial data transferred
from the transceiver to the computer. The output uses
negative logic.
TXD: The receive data is the serial data transferred
from the computer to the transceiver. The input uses
negative logic.
GND: This is the signal ground pin.
RTS: This signal is applied to the transceiver. It is used
io inhibit transmit data from the transceiver when the
computer is not ready to receive the data. The input
uses positive logic. Inhibit is requested when the level
is low.
CTS: This signal is applied from the transceiver. It is
used to inhibit transmit data from the computer when
the transceiver is not ready to receive the data. The
output uses positive logic. Transmit data is stapped
when the level is low.
CONTROL OPERATION
Most computers handle data in the form of "bits" and
"bytes", A bit is the smallest piece of information that
the computer can handle. A byte is composed of eight
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 method
is faster but more complicated, while the serial method
is slower and requires less complicated equipment. The
serial form is, therefore, a less expensive alternative.
Serial data transmission uses time-division methods
over a single line. Using a single line also offers the
advantage of reducing the number af errors due to line
noise.
Only 3 lines are required theareticaliy for contro! of the
transceiver via the computer:
+ Transmit data
+ Receive data
+ Ground
From a practical standpoint, it is also necessary to
incorporate some means of controlling when this data
transfer will occur. The computer and transceiver
cannot be allowed to send data at the same time! The
required contro! is achieved by using the RTS and CTS
lines.
For example, the transceiver is placed into the transmit
made whenever the character string "TX;" is sent from
the computer. The character string "TX;" is called a
command. ft tells the transceiver to de something.
There are numerous commands available tor control of
the transceiver. These cammands may be incorporated
into a computer program written in any high leve!
language. Programming methods vary from computer
to computer; therefore, refer to the instruction manuals
provided with the terminal program and computer.
COMMANDS
Acommand is composed of 2 alphabetical characters,
various parameters, and the terminator to signa! the end
of the command.
EXAMPLE: Cammand to set VFO A to 7 MHz
0000700000!
1 : j
! t
}
Terminator
Parameters
|
Command
COMMAND DESCRIPTION
Acommand may consist of either lower or upper case
alphabetical characters.
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