sci_instr

Module to communicate with scientific instruments via a VISA connection. Hide actual commands (e.g. SCPI) in a yaml file and access instrument features via automatically generated class properties.

Purpose

Instead of a lot of SCPI commands that you have to memorize or look up and that clutter the code:

osc.write(':CHAN4:POS 0') 
osc.write(':TRIG:LEV4 0.6')
points = osc.query(':ACQuire:POINts')

use class properties for easier access and setting of instrument properties:

osc.ch4_position = 0
osc.ch4_triglvl  = 0.6
points = osc.points

Prerequisites

You will need pyvisa (https://pyvisa.readthedocs.io/en/stable/), yaml and numpy (e.g. via anaconda https://www.continuum.io/downloads)

How to use

For usage of an existing instrument you need to import visa and the instrument class you want to use.

import visa
from sci_instr.oscilloscope import RS_RTO1044

Then generate a visa resource manager and use it in combination with the visa address of your instrument to create an instance of the instrument.

rm = visa.ResourceManager()
osc = RS_RTO1044(rm,'TCPIP0::192.168.0.11::inst0::INSTR')

How to create new instruments

For minimal usage you need to create a yaml file with your instrument commands.

readOnlyProps contain all instrument properties that are only read and that may return an arbitrary string.

readWriteProps can be read and written to and return usually doubles (if post processing of instrument answers is needed you need a subclass of Instrument and define your own _process_read_values)

readBinaryTraces usually used to transfer larger datasets in binary formats using pyvisas query_values

Example: Create a yaml config file in config\Oscilloscopes\TestOsc.yaml:

readOnlyProps:
    name        : '*IDN'

readWriteProps:
    time_range  : :TIMebase:RANGe

readBinaryTraces:
    ch1_data    : :CHAN1:WAV1:DATA

To then use your instrument use the generic Instrument class and tell it which yaml file to use for creating the class properties:

import visa
import os
from sci_instr.generic import Instrument


osc = Instrument(rm,'TCPIP0::192.168.0.11::inst0::INSTR',conffile=os.path.join('Oscilloscopes','TestOsc.yaml'))

print(osc.name)
print(osc.time_range)

Authors

• Tim Hellwig - Initial work -

See also the list of contributors who participated in this project.

License

This project is licensed under the MIT License - see the LICENSE.md file for details