Kenwood TS-990S - Manual (Page 3)

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PC CONTROL COMMAND REFERENCE GUIDE
CONTROL OPERATION
Most computers handle data in the form of “bits” and
“bytes”. A bit is the smallest piece of information a
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 of errors due to
line noise.
Theoretically, only three lines are required to control
the transceiver via the computer:
• Transmit data
• Receive data
• Ground
However, 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 control is achieved by using
the RTS and CTS lines.
For example, the transceiver is placed into the
transmit mode whenever the character string “TX;”
is sent from the computer. The character string
“TX;” is called a computer control command; it tells
the transceiver what to do. There are numerous
commands available for control of the transceiver.
These commands may be incorporated into a
computer program written in any high level language.
Programming methods vary from computer to
computer; refer to the instruction manuals provided
with the terminal program and computer.
COMPUTER CONTROL COMMANDS
Note: PC control commands will not be available when “MSQ/
PKS Pin Assignment (COM Connector)” from the Advanced
Menu is set to “On”.
A computer control command is composed of a
2-letter alphabetical command-name, a set of
parameters, and the terminator that signals the end of
the command.
Example: Command to set the Main Band VFO to 7 MHz
FA 00007000000 ;
Alphabetical command
Parameters
Terminator
Commands can be classified as shown below:
Computer
control
commands
Input command
(input to the
transceiver)
Set command
(sets a particular
condition)
Read command
(reads an answer)
Output command
(from the
transceiver)
Answer command
(transmits a
condition)
For example, note the following in the case of the above
FA command (Frequency of the Main Band VFO):
• To set the frequency to 7 MHz, the following
command is sent from the computer to the
transceiver:
“FA00007000000;” (Set command)
• To read the frequency of VFO A, the following
command is sent from the computer to the
transceiver:
“FA;” (Read command)
• When the Read command above has been
sent, the following command is returned to the
computer:
“FA00007000000;” (Answer command)
Note:
◆
Do not use the control characters 00 to 1Fh since they are
either ignored or cause a “?” answer.
◆
Program execution may be delayed while turning the Tuning
control rapidly.
◆
Receive data is not processed if the frequency is entered
from the keypad.
◆
When Power-Saving Mode is ON, you cannot start up the
transceiver using a PC command.
◆
When a PC command is used, the timer for the Automatic
Power Off is reset.
◆
When a PC command is used, the timer for the Screen
Saver is reset.