InstroDMM

class InstroDMM(

name: str | None = None,

driver: DMMDriverBase | None = None,

publishers: list[Publisher] | None = None,

config: DMMConfig | dict | Path | str | None = None,

autostart: bool = False,

**kwargs,

)

Bases: Instrument

Digital multimeter instrument. Call set_measurement_function then read, or a single read_<function>.

Initialize an InstroDMM.

Provide either config or driver, not both.

Parameters:

• name – Channel-name prefix for published data. Falls back to config.device.name when config is given.

• driver –

  Concrete DMM driver; owns its own transport:

  dmm = InstroDMM(
      "main",
      driver=Agilent34401A("ASRL3::INSTR"),
  )
  

• publishers – Publishers that receive emitted Measurement/Command data. Combined with any publishers declared in config.

• config – A DMMConfig, a dict, or a path to a JSON config file. Its measurement block is applied through the public setters on open().

• autostart – When True, open the connection and start background polling. Requires config with a measurement block, since polling cannot start without a measurement function.

• **kwargs – Default tags applied to every emitted Measurement/Command. Pass dataset_rid="<rid>" to auto-create a NominalCorePublisher (uses the on-disk ‘default’ Nominal credential).

Attributes

background_interval	Seconds between background daemon iterations (0 = no wait).
channel_names	Return an insertion-ordered snapshot of all published channel names.

Methods

add_background_daemon_function	Append method to the daemon's call list.
add_publisher	Register a publisher to receive this instrument's Measurement/Command data.
close	Close the underlying driver and stop the daemon.
define_background_daemon	Replace all daemon functions with a single method (called with the given args).
get_channel	Return the most recent length samples for channel_name from the in-memory buffer.
get_single_channel_value	Return the most recent sample for channel_name from the in-memory buffer.
open	Open the underlying driver and apply any configured measurement state.
publish	Fan data out to every configured publisher; kwargs pass through.
read	Trigger a measurement under the configured function and return it.
read_ac_current	Read AC current (amperes), selecting the function first if needed.
read_ac_voltage	Read AC voltage (volts), selecting the function first if needed.
read_dc_current	Read DC current (amperes), selecting the function first if needed.
read_dc_voltage	Read DC voltage (volts), selecting the function first if needed.
read_four_wire_resistance	Read 4-wire resistance (ohms), selecting the function first if needed.
read_resistance	Read 2-wire resistance (ohms), selecting the function first if needed.
set_aperture_nplc	Set integration time as a number of power-line cycles.
set_aperture_seconds	Set integration time (aperture) in seconds.
set_digits	Set resolution in digits.
set_measurement_function	Configure the DMM for function (DC voltage, resistance, etc.).
set_range	Set manual range; None selects auto-range.
start	Start the background daemon thread.
stop	Signal the background daemon to stop and join it.