Lakeshore 425

The Lakeshore Model 425 gaussmeter is a device which measure the magnetic field by hall sensor. This agent is used to measure the magnetic field from the superconducting magnetic bearing of the CHWP rotation mechanism and to monitoring the status of floating and rotating CHWP.

usage: python3 agent.py [-h] [--port PORT] [--mode {init,acq}]
                        [--sampling-frequency SAMPLING_FREQUENCY]

Agent Options

--port

Path to USB node for the lakeshore

--mode

Possible choices: init, acq

Starting action for the agent.

--sampling-frequency

Sampling frequency for data acquisition

Configuration File Examples

Below are useful configurations examples for the relevant OCS files and for running the agent in a docker container.

OCS Site Config

To configure the ocs-lakeshore425-agent we need to add a Lakeshore425Agent block to our ocs configuration file. Here is an example configuration block using all of the available arguments:

{'agent-class': 'Lakeshore425Agent',
'instance-id': 'LS425',
'arguments': [
  ['--port', '/dev/LS425'],
  ['--mode', 'acq'],
  ['--sampling-frequency', 1.],
]},

If you would like to chanege the setting or check the status of the lakeshore 425, the --mode argument should be 'init'.

Docker Compose

The ocs-lakeshore425-agent can be run via a Docker container. The following is an example of what to insert into your institution’s docker-compose file.:

ocs-lakeshore425-agent:
  image: simonsobs/socs:latest
  hostname: ocs-docker
  environment:
    - INSTANCE_ID=LS425
  device:
    - /dev/LS425:/dev/LS425
  volumes:
    - ${OCS_CONFIG_DIR}:/config:ro

Agent API

class socs.agents.lakeshore425.agent.LS425Agent(agent, port, f_sample=1.0)

Agent for interfacing with a single Lakeshore 425 device.

Parameters:

• agent (ocs.ocs_agent.OCSAgent) – Instantiated OCSAgent class for this Agent

• port (int) – Path to USB device in /dev/

• f_sample (float) – Default sampling rate for the acq Process

init_lakeshore(auto_acquire=False)

Task - Perform first time setup of the Lakeshore 425 Module.

Parameters:

auto_acquire (bool, optional) – Default is False. Starts data acquisition after initialization if True.

acq(sampling_frequency=None)

Process - Acquire data from the Lakeshore 425.

Parameters:

sampling_frequency (float, optional) – Sampling frequency for data collection. Defaults to the value passed to –sampling_frequency on Agent startup

Notes

The most recent data collected is stored in session data in the structure:

>>> response.session['data']
{"fields":
    {"mag_field": {"Bfield": 270.644},
     "timestamp": 1601924466.6130798}
}

operational_status()

Task - Check operational status.

zero_calibration()

Task - Calibrate the zero point.

any_command(command)

Process - Send serial command to Lakeshore 425

Parameters:

command (str) – any serial command

Examples

Example for calling in a client:

>>> client.any_command(command='*IDN?')

Notes

An example of the session data:

>>> response.session['data']
{'response': 'LSA1234'}

Supporting APIs

class socs.Lakeshore.Lakeshore425.LakeShore425(COM)

close()

command(command)

query(command)

get_id()

get_op_status()

get_field()

set_zero()