計測器に専用ソフトが無くても

IDN VENDOR-A,PSU-3010,SN421337,1.4
IDN VENDOR-B,DMM-71,SN090210,2.0
IDN VENDOR-C,TL-4,SN005150,0.9

psu1:MEAS:VOLT?  ->  +3.29505E+00
dmm1:MEAS:CURR?  ->  0.4119\r
temp1:MEAS:TEMP? ->  26.9 C

/// `+3.30000E+00` — exponent notation. Dart parses it directly.
static double exponent(String raw) => double.parse(raw.trim());

/// `0.4125\r\n` — plain, but with a carriage return that will silently
/// break a naive parse if it is not trimmed.
static double plain(String raw) => double.parse(raw.trim());

/// `24.8 C` — the unit is glued to the value. Split it off, and keep the
/// unit out of the number rather than out of the record.
static double withUnit(String raw) => double.parse(raw.trim().split(' ').first);

static const _psu = _Instrument('psu1', 'VENDOR-A', _Instrument.exponent);
static const _dmm = _Instrument('dmm1', 'VENDOR-B', _Instrument.plain);
static const _tmp = _Instrument('temp1', 'VENDOR-C', _Instrument.withUnit);

/// Lines are split on the newline only, deliberately. Dart's LineSplitter
/// would swallow a vendor's carriage return before this code ever sees it,
/// and then the one place that is supposed to know about that vendor's habit
/// would never be exercised. Terminators are a property of the instrument, so
/// they arrive intact and get dealt with once.

idn = [s.call("bench.read")["wire"] for _ in range(3)]
assert len(idn) == 3, idn                    # exponent · CR-terminated · unit-attached

after output on: 3.295 V · 0.4119 A · 26.9 C · 1.36 W
verbatim: psu1:MEAS:VOLT? -> +3.29505E+00 | dmm1:MEAS:CURR? -> 0.4119\r | temp1:MEAS:TEMP? -> 26.9 C

asked for 9 V -> meter reads 8.986 V, 40.5 C, 10.09 W

asked for 30 V -> meter reads 11.982 V (the supply is rated to 12)

/* The supply clamps to its own rating whatever it is told.
 * The screen above may ask for 30 V; this box goes to 12. */
if (v > 12.0) v = 12.0;

thirty = s.call("supply.set_volts", {"volts": 30})
assert float(thirty["volts"]) < 12.0, "the bench limit must clamp the supply"
assert thirty["over"], thirty

   asked 30 V, screen shows 11.982 V — the knob is not the reading

// The limit is the bench's, not the instrument's. A box does not know what
// the experiment considers too hot.
const tempLimit = 45.0;

$ bash verify.sh
   [1/2] bench_server (dart analyze)
No issues found!
   [2/2] open in AppPlayer, drive it, capture
bench-instruments: three instruments read, 9 V taken, 30 V clamped by the bench

cd instruments && cc -O2 -o instruments instruments.c && cd ..
( cd bench_server && dart pub get )

# In AppPlayer: add a server app — command `dart`, arguments `run bin/server.dart`,
# working directory `bench_server/`.

bash verify.sh