Three faults, one report. The slow poll asks ^TP — the KPA1500's ATU, which
a KPA500 (no ATU) never answers — and ask() dropped the whole connection on
any read timeout: a two-second stall and a reconnect every slow cycle, which
is why buttons lagged and the status read wrong. Worse, every serial reopen
toggled DTR/RTS — and those lines are the KPA500's POWER SWITCH (that is how
the Elecraft utility turns it on), so the amplifier obediently switched off
twenty seconds after its operator pressed nothing but Standby.
Silence is no longer a dead link (write errors still are), ^TP is never asked
again after one silence, the control lines are asserted once and held, and
the baud field becomes a list of the rates these amplifiers actually speak.
Two things the wiring got wrong, both visible on screen.
A KPA fell through to the PowerGenius branch of the amplifier card and was
drawn as one — titled 'POWERGENIUSXL · ELECRAFT KPA1500', with a
PowerGenius's meters and none of its own. It has a card now: OPERATE, ON
and OFF, band, power, SWR, temperature, supply, and the fault across the
end. The OPERATE button carries a tooltip saying it also clears the fault,
because that is the button an operator already has under the cursor when
they need it.
And the band-follow option was offered on it. That option exists because
an Acom POLLS a transceiver and has no command to be given a band, so
following it needs a second serial port and a rig emulator answering those
polls. The KPA has ^BN — OpsLog simply tells it, on the link it is already
using, and only when the band CHANGES. The option is gone from the KPA and
the telling is automatic.
Also: Acom rather than ACOM everywhere it is read, which is how the
company writes it. Identifiers, package names and log lines are left
alone — renaming those is churn with no reader.
One package for both amplifiers: they share the Elecraft command set — a
caret, letters, a semicolon, case-insensitive in and upper case out — the
same family as the K3/K4 panel. What differs is the transport and which
commands exist, not the grammar.
Everything here comes from the KPA1500 Programming Reference, and the
document's own examples ARE the test:
^WS1204 014; 1204 W and SWR 1.4:1 — power and SWR in one exchange
^VI513 061; 51.3 V and 61 A — volts in tenths, amps whole
^FL91; HEX, and 0x91 is 'antenna not connected?'
That last one is why the parsing is pinned rather than eyeballed: read as
decimal, 90 and 91 become 144 and 145 and match nothing, so an amplifier
shut down by high reflected power would report a fault OpsLog could not
name. SWR in tenths is confirmed by the reference too — 'expressed in
tenths, 123 is 12.3:1' — where it had only been inferred from Hamlib.
The client is question-and-answer under one lock, never two questions in
flight: the reference states there is no flow control and that commands
are paced by waiting for the reply. Fast cycle four times a second for
power, SWR and the fault; the rest once a second.
Faults are named in the operator's terms — 'the ATU found no match', not
'fault 92' — and an unknown code from a newer firmware still says
something rather than nothing.
Not wired to the app yet, and two commands are deliberately absent: ^TX
makes the amplifier transmit from software, and ^ON0 cuts the main
supplies with Wake-on-LAN as the way back. Neither belongs on a poll loop
or behind a button that can be pressed by accident.
rouggy