Yaesu FT-757GX II, Technical Supplement

Page: 13 / 70

As illustrated in the Frequency Enter Command
example, frequency parameter data is sent least­
significant digit first. The Frequency Step Com­
mand example shows how dummy data
("f/J(/J")
is
required in all other commands, preceding the
instruction byte.
Once the 5-byte command has been sent to the
transceiver, it will respond with the appropriate
change indicated on the front panel display. If
not, an error has occurred either in the data sent
or in the interface connection, so these should
PROGRAMMING
START
be inspected before the command is sent to the
transceiver again. Note that the controls on the
transceiver are not disabled when exerc1smg
external control; touching any control on the
transceiver that duplicates an externally-controlled
function will invalidate function indications on the
computer display. The external control program
may then have to be reinitialized to clear inva­
lidated variables. To avoid problems caused by
inadvertent movement of the tuning knob, the
D. LOCK command can be programmed to be
sent to the transceiver during external control
operation.
XCVR
COMMAND BYTE CODES
No.
I
2
3
4
5
6
7
8
9
10
II
DATA
FUNCTION COMMAND
I 2 3 4 5
SPLIT x x x x
,O' I
VFO-A/VFO-B SPLIT ON and OFF.
MR/VFO
x
x
x x
,0'2
Exchange operating freq. between
memory and VFO.
V.,. M
x x x x
,0'3
Write V FO data into memory.
D LOCK
x x x x
,0'4
Lock tuning dial.
Exchange operation between V FOs A
VFO A/B
x x x x
,0'5
and B.
M.,. V
x x x x
,0'6
Write memory data in�to operating VFO.
500
UP x x x x
,0'7
Step up
500
kHz
(Band Up)
500 OWN
x x x x
%8
Step down
500
kHz
(Band
Down)
CLAR
x x x x
,0'9
Activate or deactivate clarifier.
Frequency set
f � j,
,O'A Enter new operating frequency.
V�M
x x x x
,.0'8
Exchange freq. data between VFO and
memory.
"X"
=
dummy data (value irrelevant)
J) J) J) @
:
Frequency data, LSB first.
Example:
12.345.67
MHz is stored as follows.
(referring to the data locations in the Table):
(i) -67
@ -45
@ -23
® -01
Data output routines in the external computer
may have to be in machine language, as· BASIC
and other high-level languages are generally too
slow to handle the required routines during data
transfer, unless the computer is equipped for
4 800-baud output.
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