Added chroma measurement BESSY2

[JeanLucPons]

Added example on BESSY2 VA for chroma measurement.

[simoneliuzzo]

Dear @JeanLucPons

I get this error messagge:

23 Jan 2026, 13:31:57 | WARNING | OA control system binding for PyAML initialized with name 'live' and prefix='liuzzo:'
Traceback (most recent call last):
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/configuration/factory.py", line 141, in build_object
    obj = elem_cls(cfg)
TypeError: Can't instantiate abstract class EpicsR without an implementation for abstract methods 'check_device_availability', 'get_range'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/examples/BESSY2_example/bessy2-chroma.py", line 3, in <module>
    sr = Accelerator.load("BESSY2Chroma.yaml")
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/accelerator.py", line 173, in load
    return Accelerator.from_dict(config_dict)
           ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/accelerator.py", line 143, in from_dict
    return Factory.depth_first_build(config_dict, ignore_external)
           ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/configuration/factory.py", line 175, in depth_first_build
    obj = self.depth_first_build(value, ignore_external)
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/configuration/factory.py", line 165, in depth_first_build
    obj = self.depth_first_build(e, ignore_external)
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/configuration/factory.py", line 175, in depth_first_build
    obj = self.depth_first_build(value, ignore_external)
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/configuration/factory.py", line 180, in depth_first_build
    return self.build_object(d, ignore_external)
           ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/pyaml/configuration/factory.py", line 144, in build_object
    raise PyAMLConfigException(
        f"{str(e)} when creating '{type_str}.{cls_name}' {location_str}"
    ) from e
pyaml.common.exception.PyAMLConfigException: Can't instantiate abstract class EpicsR without an implementation for abstract methods 'check_device_availability', 'get_range' when creating 'pyaml_cs_oa.epicsR.EpicsR' /Users/liuzzo/Desktop/pyaml_workshop_dev_instruction/pyaml/examples/BESSY2_example/BESSY2Chroma.yaml at line 18, column 5.

[simoneliuzzo]

@JeanLucPons:
I updated the pyaml-cs-oa and now it is running ok.
thank you

[simoneliuzzo]

Dear @JeanLucPons
if I switch to sr.design then the measurement is not ok

but the output is correct
(pyaml_bessy2_venv) macliuzzo:BESSY2_example liuzzo$ python bessy2-chroma.py 23 Jan 2026, 13:37:41 | WARNING | PyAML OA control system binding (0.1.1) initialized with name 'live' and prefix='liuzzo:' Moment compaction factor: 0.0007079019672909947 [1.7494258 3.01929974]