instrutech-gauges

Python drivers for InstruTech gauges over serial or TCP serial gateways.

Install

uv add instrutech-gauges

Or for local development:

uv sync

Available drivers

• VGC301
• HornetIGM402
• Public base class for custom devices: InstruTechAsciiGauge

Quick start (VGC301)

from instrutech_gauges import SerialTransport, VGC301

t = SerialTransport(port="/dev/ttyUSB0", baudrate=19200, timeout_s=0.3)
g = VGC301(t, address=1)

with g:
    print(g.read_sw_version())
    print(g.read_pressure_torr())
    g.set_trip_point(1, "on_below", 4.00e2)
    print(g.read_trip_point(1, "on_below"))

Quick start (Hornet IGM402)

from instrutech_gauges import HornetIGM402, SerialTransport

t = SerialTransport(port="/dev/ttyUSB0", baudrate=19200, timeout_s=0.3)
g = HornetIGM402(t, address=1)

with g:
    print(g.read_sw_version())
    print(g.read_system_pressure_torr())
    print(g.read_pressure_unit())

Firmware notes for HornetIGM402:

• SES emission setting responses like 0.1MA_EM / 4.0MA_EM are parsed.
• RU accepts long unit tokens (TORR, MBAR, PASCAL).
• Optional command families (RU/SU, RDIG*) raise InstruTechUnsupportedCommandError on firmware that returns SYNTX ER.
• Socket transport defaults to \r command termination.

Without context manager (with)

Use explicit open() / close() with try/finally:

from instrutech_gauges import SerialTransport, VGC301

t = SerialTransport(port="/dev/ttyUSB0", baudrate=19200, timeout_s=0.3)
g = VGC301(t, address=1)

g.open(probe=True)
try:
    print(g.read_sw_version())
    print(g.read_pressure_torr())
finally:
    g.close()

from instrutech_gauges import HornetIGM402, SerialTransport

t = SerialTransport(port="/dev/ttyUSB0", baudrate=19200, timeout_s=0.3)
g = HornetIGM402(t, address=1)

g.open(probe=True)
try:
    print(g.read_sw_version())
    print(g.read_system_pressure_torr())
finally:
    g.close()

Public base class

InstruTechAsciiGauge exposes shared protocol and transport helpers for building new drivers:

• framing/parsing (#xx...<CR>, *xx...<CR>)
• query() / query_float() / command_prog_ok()
• serial reconfiguration (set_baud, set_parity, set_serial_comm)
• common Mini-Convectron-style commands (VER, RD, TS, TZ, SL/SH, RL/RH, FAC, RST)

Minimal custom driver:

from instrutech_gauges import InstruTechAsciiGauge

class MyGauge(InstruTechAsciiGauge):
    def read_custom_value(self) -> float:
        return self.query_float("RDCUSTOM")

Transport

• SerialTransport: local serial via pyserial
• SocketTransport: TCP serial gateways (raw TCP)

SocketTransport defaults to CR (\r) command termination. If your gateway expects CRLF, override it:

from instrutech_gauges import SocketTransport

t = SocketTransport("192.168.1.50", 4001, timeout_s=1.0, write_terminator=b"\r\n")

Runtime serial reconfiguration (set_baud, set_parity) is supported only with SerialTransport.

VGC301 serial notes

Per the VGC301 manual, SB* / SP* / SA* / FAC require RST before they take effect.

• VGC301.set_baud(...) defaults to reset_after=True
• VGC301.set_parity(...) defaults to reset_after=True
• For ODD/EVEN parity, data bits default to 7; for NO parity, data bits default to 8

Error handling

Typical exceptions:

• InstruTechTimeoutError
• InstruTechProtocolError
• InstruTechDeviceError
• InstruTechUnsupportedTransportOperationError

Release flow

• CI runs on every push and PR (.github/workflows/ci.yml).
• PyPI publish runs only on tags that start with v (.github/workflows/publish.yml).
• Publish is blocked unless tag version matches pyproject.toml version exactly.

Example release:

git tag v0.1.1
git push origin v0.1.1

Configure PyPI Trusted Publisher for this repository so the publish workflow can upload without storing an API token.