This repository contains the official SiLA 2 drivers for a variety of CETONI devices. These SiLA 2 drivers are based on the CETONI SDK for Python in order to control the devices.

This repository also contains SiLA 2 drivers for a growing number of third-party devices that can be used in combination with CETONI devices.

• Getting Started
  • Installation
    • sila_cetoni
    • CETONI SDK
  • Creating a device configuration
  • Running SiLA 2 servers
  • sila-cetoni CLI options reference
• Troubleshooting
  • 'undefined symbol: __atomic_exchange_8' on Raspberry Pi
  • 'version `GLIBC_2.29' not found' on Raspberry Pi
• Modifying the drivers
• Contributing

Note
These SiLA 2 drivers were developed and tested under Windows and Linux (Ubuntu 19.04 and Raspbian Buster on a Raspi 3B+) and are therefore expected to work on these systems. Other operating system should work as well, but have not been tested yet!

Install the sila_cetoni package with

pip install .

It is recommended to install these things in a virtual environment to not interfere with anything in your system's environment.
This will install all Python dependencies for sila_cetoni most notably sila_python as well as sila_cetoni itself. This means you can not only use the provided console script to run your CETONI device configurations but also build upon the SiLA 2 implementations and build you own applications.

If you would like to use the CETONI SiLA 2 drivers to control CETONI devices, then you need to install the CETONI SDK with Python Integration.

For instructions on how to install the CETONI SDK for Python on your system and get a valid configuration for your devices see the CETONI SDK Documentation.
On Linux be sure to also install the correct SocketCAN driver (either SysTec or IXXAT depending on your CETONI base module).

Note
The CETONI SDK is not strictly necessary any more if you only use sila_cetoni to control non-CETONI devices!

Note
If your system contains any CETONI devices you always need a valid CETONI device configuration created with the CETONI Elements software in order to use sila_cetoni.
If you only want to control a Sartorius balance, for example, you don't need a CETONI device configuration.
In any case you need a sila_cetoni device configuration.

Starting from version v1.2.0, sila_cetoni uses a device configuration concept similar to the device configurations you can create with the CETONI Elements software.
sila_cetoni's device configuration consists of a single JSON file that describes all the devices you want to have SiLA 2 server for.

The basic structure of this configuration file looks as follows:

{
  "$schema": "https://raw.githubusercontent.com/CETONI-Software/sila_cetoni_application/main/sila_cetoni/application/resources/configuration_schema.json",
  "version": 1,
  "cetoni_devices": {
      "device_config_path": "C:/CETONI_SDK/config/testconfig_qmixsdk"
  }
}

This file says that you have no third-party devices and that you want to use the CETONI device configuration located at C:/CETONI_SDK/config/testconfig_qmixsdk.

As you can see, you still need the CETONI device configuration created with CETONI Elements in order to create SiLA 2 servers for these devices.

Now, if you want to add devices from other vendors that are also supported by sila_cetoni, you need to add these like this:

{
  "$schema": "https://raw.githubusercontent.com/CETONI-Software/sila_cetoni_application/main/sila_cetoni/application/resources/configuration_schema.json",
  "version": 1,
  "cetoni_devices": {
      "device_config_path": "C:/CETONI_SDK/config/testconfig_qmixsdk"
  },
  "devices": {
    "Sartorius Balance": {
      "type": "balance",
      "manufacturer": "Sartorius",
      "port": "COM4"
    }
  }
}

Each device is defined in its own object and needs at least the type and manufacturer properties. Depending on the device you might also need additional properties, e.g. a serial port as shown here with the balance.
The name of the property that is used to define a device is used later as the name of the SiLA 2 server that gets created for this device, i.e. the SiLA 2 server created in this example would have th name Sartorius Balance.

You can add as many devices as you like in the devices object, e.g. if you have two balances you might have the following configuration:

{
  "$schema": "https://raw.githubusercontent.com/CETONI-Software/sila_cetoni_application/main/sila_cetoni/application/resources/configuration_schema.json",
  "version": 1,
  "cetoni_devices": {
      "device_config_path": "C:/CETONI_SDK/config/testconfig_qmixsdk"
  },
  "devices": {
    "Sartorius Balance 1": {
      "type": "balance",
      "manufacturer": "Sartorius",
      "port": "COM4"
    },
    "Sartorius Balance 2": {
      "type": "balance",
      "manufacturer": "Sartorius",
      "port": "COM5"
    }
  }
}

Note
The $schema property is not strictly necessary but VS Code can use that to provide some help when writing the configuration file. sila_cetoni will use that schema to validate that the configuration file you provide is correct regardless of whether $schema is present or not.

In addition to defining the devices you want to use you can also override most of the command line options that sila-cetoni accepts. That way you can persistently store the options to use with each configuration you create.

The following shows a complete configuration file with all options set to their default values:

{
  "$schema": "https://raw.githubusercontent.com/CETONI-Software/sila_cetoni_application/main/sila_cetoni/application/resources/configuration_schema.json",
  "version": 1,
  "cetoni_devices": {
      "device_config_path": "C:/CETONI_SDK/config/testconfig_qmixsdk"
  },
  "devices": {
    "Sartorius Balance": {
      "type": "balance",
      "manufacturer": "Sartorius",
      "port": "COM4"
    }
  },
  "server_ip": null,
  "server_base_port": 50051,
  "regenerate_certificates": false,
  "log_level": "info",
  "log_file_dir": null,
  "scan_devices": false
}

See the CLI options reference below for mor information about what the individual options do.

Running the corresponding SiLA 2 servers for your system is always done through the sila-cetoni console script that gets installed by pip.

Simply run the script giving it the path to the sila_cetoni device configuration file as an argument:

sila-cetoni <path/to/your/device_config.json>

By using this device configuration file concept you can easily create multiple device configurations and switch between them by just changing the argument that you call sila-cetoni with.

To se a list of all available command line options run

sila-cetoni --help

Note
If you have problems running the sila-cetoni console script try running the application via the module syntax:

$ python -m sila_cetoni.application <arguments...>

Also, in case you get the error ModuleNotFoundError: No module named 'qmixsdk' you have to point the script to the correct location of the CETONI SDK. This can easily be done by setting the CETONI_SDK_PATH environment variable before calling sila-cetoni.

You can play around with the servers and their features by using the freely available SiLA Browser or even CETONI Elements, for example.
Or you can also write your own SiLA Client software using the Python or any other of the reference implementations of SiLA 2.

The following table shows all available CLI options that the sila-cetoni console script (or the sila_cetoni.application.__main__ module) understands:

You might get the following error when trying to run the driver on a Raspberry Pi:

Traceback (most recent call last):
  File "/home/pi/sila_cetoni/sila_cetoni.py", line 43, in <module>
    from application.application import Application, DEFAULT_BASE_PORT
  File "/home/pi/sila_cetoni/application/application.py", line 35, in <module>
    from sila2lib.sila_server import SiLA2Server
  File "/home/pi/sila_python/sila_library/sila2lib/sila_server.py", line 36, in <module>
    import grpc
  File "/home/pi/.local/lib/python3.9/site-packages/grpc/__init__.py", line 22, in <module>
    from grpc import _compression
  File "/home/pi/.local/lib/python3.9/site-packages/grpc/_compression.py", line 15, in <module>
    from grpc._cython import cygrpc
ImportError: /home/pi/.local/lib/python3.9/site-packages/grpc/_cython/cygrpc.cpython-39-arm-linux-gnueabihf.so: undefined symbol: __atomic_exchange_8

This is a known bug in gRPC (grpc/grpc#20400) and there exists a workaround, too (opencv/opencv#15278 (comment)):
This workaround is already included in sila_cetoni/application/__init__.py:

# ...
env["LD_PRELOAD"] = "/usr/lib/arm-linux-gnueabihf/libatomic.so.1.2.0"  #< workaround for grpc/grpc#20400
#...

If you try to run newer gRPC versions on Raspberry Pi it might happen that you get ate following error:

Traceback (most recent call last):
  ...
  File "/home/pi/sila_cetoni/sila_cetoni/application/sila_cetoni/application/__main__.py", line 19, in <module>
    from .application import Application
  File "/home/pi/sila_cetoni/sila_cetoni/application/sila_cetoni/application/application.py", line 36, in <module>
    from sila2.server import SilaServer
  File "/home/pi/.local/lib/python3.7/site-packages/sila2/server/__init__.py", line 2, in <module>
    from sila2.server.metadata_dict import MetadataDict
  File "/home/pi/.local/lib/python3.7/site-packages/sila2/server/metadata_dict.py", line 5, in <module>
    from sila2.framework import DefinedExecutionErrorNode, FullyQualifiedMetadataIdentifier, Metadata
  File "/home/pi/.local/lib/python3.7/site-packages/sila2/framework/__init__.py", line 1, in <module>
    from sila2.framework.abc.sila_error import SilaError
  File "/home/pi/.local/lib/python3.7/site-packages/sila2/framework/abc/sila_error.py", line 8, in <module>
    import grpc
  File "/home/pi/.local/lib/python3.7/site-packages/grpc/__init__.py", line 22, in <module>
    from grpc import _compression
  File "/home/pi/.local/lib/python3.7/site-packages/grpc/_compression.py", line 15, in <module>
    from grpc._cython import cygrpc
ImportError: /lib/arm-linux-gnueabihf/libm.so.6: version `GLIBC_2.29' not found (required by /home/pi/.local/lib/python3.7/site-packages/grpc/_cython/cygrpc.cpython-37m-arm-linux-gnueabihf.so)

The problem is that the binaries uploaded to PyPI require libc version 2.29. Luckily, the grpcio and grpcio-tools packages are also available from piwheels and those work with libc 2.28 (which is installed on Raspberry Pi OS 10).
So, simply uninstall the existing packages and reinstall them from piwheel:

pip3 uninstall grpcio grpcio-tools
pip3 install grpcio grpcio-tools -i https://www.piwheels.org/simple

You are, of course, free to play around with the code inside this repository.

The implementation files have been generated using the sila2-codegen script that comes with sila_python. Refer to its documentation to see how to add and update existing feature implementations.

This repository uses a separate python package for each Feature Category, e.g. all SiLA Features of the 'de.cetoni/pumps.syringepumps' category are implemented in the sila_cetoni.pumps.syringepumps package.

You can change and improve the current implementations, create new Commands, Properties, or even whole new SiLA 2 Features. If you think your changes might be interesting for us and other users as well, feel free to open a pull request on the GitHub project page. Also, if you have any questions or problems with the drivers, just open an issue and we'll try to help you.