MD6 is FSK on a Kenwood and DATA on a K3/K4. kenwoodModeToADIF decoded the
digit unconditionally as RTTY, so OpsLog contradicted the mode it had just
set: SetMode writes MD6 for a digital mode on an Elecraft, then ReadState
parsed the IF frame back as RTTY.
A K3 running FT8 therefore showed RTTY in the status bar, logged its QSOs on
RTTY, and — through the shared CAT server — told WSJT-X/JTDX the rig sat in
RTTY while they had just asked for a data mode. Found in a K3 operator's log:
every cat:state line read mode=RTTY on 21.074 FT8, two lines after OpsLog's
own "MD6;".
The digit now resolves to the configured digital mode whenever MD6 means DATA
on this rig — the Elecraft backend, and the "DATA A - MD6" data-mode option
that exists for it. A plain Kenwood still reads MD6 as RTTY.
No single Kenwood mode digit fits every rig for a data mode: a K3/K4 wants
DATA (MD6), a TS-590SG/TS-990S data mode is a USB modifier set on the rig,
and MD6 on a plain Kenwood is FSK/RTTY. So the operator now chooses in
Settings → CAT: USB (default), DATA (MD6), or leave the rig's mode unchanged.
Only soundcard/data modes (FT8, PSK, JT…) follow this; RTTY/FSK stays its own
native mode, and voice/CW are untouched (isKenwoodDataMode + test).
A sixth CAT backend, talking to a TS-590/890/990/2000 over its serial port with
no OmniRig in between — frequency, mode, VFO, split and PTT. Elecraft K3/K4 and
the "Kenwood" setting on other radios speak the same dialect.
The protocol was not researched from scratch: internal/catemu already ANSWERS
these commands, pretending to be a TS-2000 so an ACOM amplifier follows OpsLog.
The IF frame layout here is read from the same format string catemu emits, so
the two halves of the repository agree by construction — and the test caught my
own fixture being one character short, which is exactly the error that layout
invites.
Design notes worth keeping:
- IF; is the poll. One frame carries frequency, TX state, mode, VFO and split,
so simplex operation costs a single round trip; the other VFO is only asked
for when split is actually on.
- FA/FB take ELEVEN digits here where Yaesu uses nine. That is the likeliest
place to copy the Yaesu backend and be wrong by a factor of a hundred, so it
has its own test.
- Every lesson the Yaesu backend learned the hard way is built in from the
start: replies matched to the command that asked, "?;" remembered so a poll
stops paying a timeout for an unsupported command, the serial handle closed
before reopening, and a rig that answers nothing reported as absent rather
than "connected".
Untested on hardware — I have no Kenwood here. The frame parsing is covered by
tests against catemu's own format.
rouggy