Pulsar Python SDK

Commands and parameters

Pulsar Python SDK distinguishes runtime commands from stored or readable parameters.

Primary command

A standalone actuator accepts a scalar command:

actuator.set_command(0.5)

The unit depends on the configured mode:

Mode	Unit
`TORQUE`	N·m
`VELOCITY`	rad/s
`POSITION`	rad
`IMPEDANCE`	position in rad

Commands must be finite and are accepted only in DRIVE_ACTIVE.

Mode-specific command fields

from pulsar_sdk import ControlParams

actuator.set_command({
    ControlParams.COMMAND: 0.5,
    ControlParams.VELOCITY_KP: 1.2,
})

Every mapping requires ControlParams.COMMAND. Optional fields may use NaN to keep their current value.

Field	Allowed modes
`D_AXIS_CURRENT_KP`, `D_AXIS_CURRENT_KI`	torque
`Q_AXIS_CURRENT_KP`, `Q_AXIS_CURRENT_KI`	torque
`FEEDFORWARD_GAIN`	velocity, position, impedance
`VELOCITY_KP`, `VELOCITY_KI`	velocity, position
`TORQUE_FEEDFORWARD`	velocity, position, impedance
`POSITION_KP`	position
`IMPEDANCE_STIFFNESS`, `IMPEDANCE_DAMPING`, `IMPEDANCE_INERTIA`	impedance
`IMPEDANCE_VELOCITY_COMMANDED`, `IMPEDANCE_ACCELERATION_COMMANDED`	impedance

Group commands

A group or platform batch may select only some members. Omitted actuators keep their previous device command, and every selected actuator mapping must include ControlParams.COMMAND.

arm.set_commands({
    "shoulder": {ControlParams.COMMAND: 0.2},
    "elbow": {ControlParams.COMMAND: -0.2},
})

Direct batch failures raise CommandTransmissionError. Its successful_members field identifies writes completed before the failure.

Parameters

Read parameters with enum identity preserved:

from pulsar_sdk import Parameters

values = actuator.read_parameters((
    Parameters.TORQUE_LIMIT,
    Parameters.POSITION_KP,
))

Write parameters only while drive output is inactive:

actuator.set_parameters({
    Parameters.TORQUE_LIMIT: 2.0,
    Parameters.POSITION_KP: 0.8,
})

Use dedicated methods for mode, commands, gain presets, address, telemetry rate, and persistence.

Unified group or platform updates

Parameter and preset methods accept unify=True to apply one value across represented actuators. Commands intentionally do not support unify=True.

Atomicity

Validation occurs before transmission, but parameter, preset, and member command writes are not transactional. A transport failure can leave earlier writes applied and later writes unapplied.

Direct batch failures raise CommandTransmissionError; successful_members identifies writes completed before the failure. Callback-path transmission failures instead latch a host error and run the configured safety policy.

See the API reference for every parameter and exact validation rule.