Yaesu FT-891 Reference Book page 3

CAT
( Computer Aided Transceiver )
A computer control command is composed of an
alphabetical command, various parameters, and
the terminator that signals the end of the control
command.
Example:
Set the VFO-A frequency to 14.250000 MHz.
FA 014250000 ;
 
Command Parameter Terminator
There are three commands for the FT-891 as
shown below:
Set command: Set a particular condition
Read command: Reads an answer
Answer command: Transmits a condition
For example, note the following case of the FA
command (Set the VFO-A frequency):
 To set the VFO-A frequency to 14.250000 MHz, the
following command is sent from the computer to the
transceiver:
"FA014250000;" (Set command)
 To read the VFO-A frequency, the following com-
mand 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:
"FA014250000;" (Answer command)
Alphabetical Commands
A command consists of 2 alphabetical characters.
You may use either lower or upper case charac-
ters. The commands available for this transceiver
are listed in the "PC Control Command Tables" on
the following pages.
Control Command

(to the FT-891)
(from the FT-891)
(from the FT-891)
2
Operation
Parameters
Parameters are used to specify information neces-
sary to implement the desired command.
The parameters to be used for each command are
predetermined. The number of digits assigned to
each parameter is also predetermined. Refer to
the "Control Command List" and the "Control Com-
mand Tables" to configure the appropriate parame-
ters.
When configuring parameters, be careful not to
make the following mistakes.
For example,
when the correct parameter is "IS0+1000" (IF
SHIFT):
IS01000;
Not enough parameters specified (No direction (+)
given for the IF shift)
IS0+100;
Not enough digits (Only three frequency digits
given)
IS0_+_1000;
Unnecessary characters between parameters
IS0+10000;
Too many digits (Five frequency digits given)
Note: If a particular parameter is not applicable to
the FT-891, the parameter digits should be filled
using any character except the ASCII control codes
(00 to 1Fh) and the terminator (;).
Terminator
To signal the end of a command, it is necessary to
use a semicolon (;). The digit where this special
character must appear differs depending on the
command used.
FT-891 CAT Operation Reference Book