Cat System Computer Control; Data Returned From Ft-890; Status Update Data Organization - Yaesu FT-890 Operating Manual

CAT System Computer Control
The CAT (Computer Aided Transceiver) Sys-
tem in the FT-890 provides control of frequency,
mode, VFO, memory and other settings by the
operator's external personal computer. This al-
lows multiple control operations to be fully auto-
(
mated as single mouse click or keystroke
1
operations on the computer keyboard.
b Serial data is passed at TTL levels (0 and +5V)
t
via SO (serial output) and SI (serial input) pins 2
E
and 3 of the CAT jack on the rear panel of the
i
transceiver, at 4800 bits/s. CAT jack pinout is
shown on page 9. Each byte sent consists of one
.
start bit, 8 data bits, no parity and two stop bits:
One byte, sent left-bright
All commands sent to the transceiver must
consist of blocks of five bytes each, with up to 200
ms between each byte. The last byte sent in each
block is the instruction opcode, while the first four
bytes of each block are arguments: either pa-
rameters for that instruction, or dummy values
(to pad the block out to five bytes):
5-Byte Command Block, Sent left-to-right
I
4th arg
byte
(
3rd arg byte
1
2nd arg byte
I
1st arg byte
1
Opcde
1
There are twenty-six instruction opcodes for
the FT-890, listed in the table on the next page.
Notice that several instructions require no spe-
cific parameters, but every command block sent
to the transceiver must consist of five bytes.
The CAT control program in the computer
must construct the 5-byte block by selecting the
appropriate instruction opcode, organizing the
parameters, if any, and providing unused (dum-
my) argument bytes for padding (dummy bytes
-
may have any value). The resulting five bytes are
then sent, opcode last, to the SI serial input pin of
the CAT jack on the transceiver.
Example: Tune to 14.25000 MHz;
First determine the opcode for the desired
instruction (see the CAT Commands table,
next page). These opcodes should be stored in
the program so they can be looked up when
the user requests the corresponding com-
mand. In this case the instruction is "Set Op
Freq", so the opcode is OAh. Small "h"s fol-
lowing each byte value indicate hexadecimal
(base 16) values.
0
Build the four argument byte values from the
desired frequency by breaking it into 2-digit
blocks (BCD "packed decimal" format). Note
that a leading zero is always required in the
hundred's-of-MHz place (and another in the
ten's-of-MHz if below 10 MHz).
0
The resulting 5-byte block should look like
this (again, in hexadecimal format):
Bytevalue OAh
1
Olh 42h 50h
1
OOh
Set Op
Content
of Freq.
MHz 10's 8 1' s 100's 8
this byte
OWs 8 1
our
of
of
,
O, s of
Hz
opcode
10' s of MHz kHz
0
Send these five bytes to the transceiver, in
reverse order from that shown above
-
from
right-to-left (see the examples on page 34).
Data Returned From FT-890
The Status Update, Read Flags and Read Meter
commands cause the FT-890 to report various
operational and internally stored settings on the
SO (serial output) line:
Status Update causes the FT-890 to return all or
portions of its RAM table (up to 649 bytes).
Read Flags obtains only the first 3 bytes (the
Status Flags) from the RAM table, plus 2 extra
"filler" bytes (08h and 41 h),
Read Meter returns the meter deflection (0 -
OFTh) repeated in four bytes, followed by one
"fillei' byte (OF7h).
Each returned byte may be delayed by an
interval determined by the Pacing command (0
to 255 ms in 1-ms steps). This delay is initially
zero until the Pacing command is sent. This al-
lows returned data to be read and processed by
even very slow computers. However, you
should set it as short as your computer will al-
low, to minimize the inconvenience of the delay.
In the worst case, when the radio is to return all
649 bytes of internal data, about 1.4 seconds is
required with "0"-length delay selected, but al-
most 3 minutes if the maximum delay is selected!
Status Update Data Organization
The 649 bytes of Update data is organized as
shown at the top of the page after next. Aside
from the Read Flags command, different portions
of this data can be returned in blocks of 1,18,19
or 649 bytes, depending on the parameters of the
Update command sent by the computer. The de-
tails of these commands follow the descriptions
of the data.
page
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