OpenMHS family: qcodes

QCoDeS instruments through QcodesDriver

Generated by MHS/registry/build_registry.py on 2026-10-20T00:00:00Z from 26 registry records and their task cards. A plan, not a conformance claim.

• bridge_status: available
• helper: QcodesDriver
• exemplar: MHS/drivers/labs/qcodes__qcodes_contrib_drivers

Launch

Every driver package starts the same way; per-repo configuration (environment id, model path, port, baud rate, VISA resource) lives in the package's driver.py, never in launch flags:

mhs serve <driver-dir>

A package is done when python3 -m mhs.driver check <driver-dir> --backend fake exits 0 (evidence contract_checked; a fake never yields an MHS-Device level).

Registry coverage

• Repos: 26
• Decisions: bridge-runtime 2, family-config 3, reference 4, skip 17
• Waves: 3: 1, 5: 2, 9: 23
• Dispatchable now: 0
• Modes: hardware 6, simulated 4

Applicability

QCoDeS instrument classes: triage rule 9, family:qcodes. QcodesDriver is a configuration-only helper over the Python-object bridge. Each field is a Field in parameters plus one parameter_bindings entry: parameter (the attribute path of a Parameter), get: True, set (equal to Field.writable), timeout_ms (1..60000) and source_ref (the path:LINE[-END] of its constructor). Gate G7 proves a self.<name> = Parameter(...) assignment in __init__ of the card's entry class or its in-clone ancestry, with Parameter imported from qcodes.parameters and an explicit get_cmd (and set_cmd for a write); a same-file factory needs factory_ref. Parameters created by add_parameter, channel lists, submodules or dynamic factories are not provable today, and most QCoDeS drivers use add_parameter: such a card stops blocked with the G7 finding QCODES_PARAMETER_SOURCE.

The PM100D exemplar serves a Thorlabs PM100D optical power meter (R1): seven Parameters, two writes through cap.device.configure.v1 (one Limit.operator_required), the stop write("ABOR") (the abort command the source sends before it re-initializes a measurement), and a source-cited reason for every Parameter it does not serve. The QCoDeS driver guide gives the complete contract.

Capability mapping

Class ids come from python3 -m mhs.driver catalog search <words>. The deprecated classes cap.device.describe.v1, cap.world.state.v1, cap.world.snapshot.v1 and cap.world.restore.v1 are replaced by the protocol methods mhs.devices.get, mhs.resource.read, mhs.snapshot and mhs.restore.

Safety

The risk floor of a device is the highest catalogue risk_class of its classes (CAP-017); a driver may declare a higher risk, never a lower one. Hardware at R1 or above needs a native stop (safety_bindings.estop) and a non-empty safe state. Sources, heaters, magnets and RF outputs: parameter validators are not safety limits, risk follows the hazard table of the safety specification, and a model-authored R2 or R3 package never runs its hardware backend before a human signs reviewed_by. Cancelling a Parameter set is not a stop acknowledgement.

Fidelity

A source-shaped fake holds one stand-in per bound Parameter (get(), and set() where the upstream has a set_cmd) plus the instrument methods the driver calls, with placeholder values typed as the upstream parsers return them. It yields contract_checked evidence only: VISA timing, SCPI error queues and instrument state machines are not modelled.

Pitfalls

Contributed drivers vary in quality: check every parser, scale and set_cmd placeholder against the source. A MEAS:...? read reconfigures the instrument; a constructor that writes settings belongs to the hardware factory, not to a capability.

First task cards

• gh.qcodes/qcodes_contrib_drivers: family-config, wave 3, rank 17, MHS/registry/tasks/labs/qcodes__qcodes_contrib_drivers.json
• gh.aalto-qcd/qickodes: family-config, wave 5, rank 9, MHS/registry/tasks/labs/aalto-qcd__qickodes.json
• gh.qcoherence/qcodes-drivers: family-config, wave 5, rank 44, MHS/registry/tasks/labs/qcoherence__qcodes-drivers.json
• gh.microsoft/qcodes: bridge-runtime, wave 9, rank 24, MHS/registry/tasks/labs/microsoft__qcodes.json
• gh.sldesnoo-delft/q1simulator: bridge-runtime, wave 9, rank 71, MHS/registry/tasks/labs/sldesnoo-delft__q1simulator.json

Sources

• Task cards: MHS/registry/tasks/<track>/<owner>__<repo>.json (schema/taskcard.schema.json).
• Triage rules and the helper table: MHS/registry/triage.py; curated decisions: MHS/registry/overrides/.
• Driver API and gate: MHS/sdk/docs/driver-authoring.md; exemplars: MHS/drivers/.
• QCoDeS driver contract and driver authoring.
• PM100D exemplar fake, tests, source facts and result/evidence scope.