pyvisa-ar488 2026.2.25

PyVISA backend for AR488/Prologix GPIB-USB adapters

pyvisa-ar488

PyVISA backend for AR488 and Prologix GPIB-USB/TCP adapters.

Lets you use standard pyvisa and pymeasure code to talk to IEEE-488 (GPIB) instruments through inexpensive AR488 or Prologix-compatible adapters.

Quick Start

pip install pyvisa-ar488

import pyvisa

# Serial adapter (e.g. Arduino Nano / ESP32 with AR488 firmware)
rm = pyvisa.ResourceManager("@ar488")
print(rm.list_resources())          # scans bus: ('GPIB0::5::INSTR', 'GPIB0::22::INSTR', ...)

instr = rm.open_resource("GPIB0::22::INSTR")
print(instr.query("*IDN?"))         # 'KEITHLEY INSTRUMENTS INC.,MODEL 2400,...'
print(instr.query("MEAS:VOLT:DC?")) # '-1.234567E-03'

Transports

Serial (default)

The adapter is auto-detected on /dev/ttyUSB0 at 115200 baud. Override via environment or constructor:

from pyvisa_ar488 import AR488VisaLibrary

lib = AR488VisaLibrary.from_serial(port="/dev/ttyACM0", baudrate=115200)
rm = pyvisa.ResourceManager(lib)

TCP (WiFi-connected ESP32)

lib = AR488VisaLibrary.from_tcp(host="192.168.1.100", port=23)
rm = pyvisa.ResourceManager(lib)

Bridge mode (mcgpib integration)

When used inside mcgpib, the backend shares the existing async connection instead of opening a new one:

lib = AR488VisaLibrary.from_bridge(bridge_connection, event_loop)
rm = pyvisa.ResourceManager(lib)

CLI

Scan a bus from the command line:

# Serial
pyvisa-ar488 --port /dev/ttyUSB0

# TCP
pyvisa-ar488 --host 192.168.1.100 --tcp-port 23

How it works

pyvisa discovers backends by looking for pyvisa_<name> packages. pyvisa-ar488 registers as the @ar488 backend. When you open a resource, the backend translates pyvisa's read/write/poll calls into AR488 ++ command sequences:

pyvisa call	AR488 commands
rm.list_resources()	++findlstn
instr.write("*RST")	++addr 22 then *RST
instr.read()	++read eoi
instr.query("*IDN?")	++addr 22, *IDN?, ++read eoi
instr.read_stb()	++spoll 22
instr.assert_trigger()	++trg
rm.send_ifc()	++ifc

The init sequence configures the adapter for machine-parseable output: ++verbose 0, ++prompt 0, ++auto 0, ++mode 1, ++eoi 1, ++eos 0.

Compatible adapters

• AR488 (Arduino / ESP32)
• Prologix GPIB-USB
• Any adapter using the Prologix ++ command protocol

Requirements

• Python 3.11+
• pyvisa >= 1.13
• pyserial >= 3.5

License

MIT