Refactoring#
The zhinst-qcodes package exists for several years and as grown a lot in that time. More and more device where added and the expectations and stability request got stronger and stronger. zhinst-qcodes is based on zhinst-toolkit a high level driver on top of the native LabOne API package (zhinst-core). Meaning it shares the same functionalities but also the same problems.
To just mention a few of them:
Long setup times
Missing nodes
Slow response times
…
Since more and more people start using python to interface with our instruments we decided that zhinst-toolkit should become the package that can be used by all of our customers for all of our devices. So ensure long term stability and also full feature support a complete redesign of the architecture was necessary. The new zhinst-toolkit now offer full feature support for all our devices, is stable, properly tested and actively maintained by the LabOne team at Zurich Instruments.
zhinst-qcodes also benefits from the redesign since it is based on zhinst-toolkit since the beginning. The benefits include low setup times and fast responses, similar to the low level LabOne API. But these benefits also come with the price of a severe api changes. The architecture and the way to use zhinst-qcodes from a user perspective more or less completely changes. In the following we will try to help with the transition to the new zhinst-qcodes driver. But we know that a lot of feature have been removed in order to align with LabOne and if you encounter any functionality no longer accessible feel free to contact the Zurich Instruments support so we can help you out.
The biggest change is probably the starting point. Instead of creating instances of the instruments directly the user now starts by creating a session to a data server. Since that is the underlying architecture of LabOne as well it seamlessly integrates into the Zurich Instruments ecosystem.
>>> from zhinst.qcodes import ZISession
>>> session = ZISession("localhost")
The individual device objects can be created from that session. Either by accessing them directly, in case they are already connected, or by connecting them.
>>> session.devices.visible()
['dev1234', 'dev5678']
>>> session.devices.connected()
['dev1234']
>>> session.devices['dev1234']
<ZIBaseInstrument: zi_XXXX_dev1234>
>>> session.connect_device('dev5678')
<ZIBaseInstrument: zi_XXXX_dev5678>
Since all devices share the same session the resource consumption is kept to a minimum. Of course one can create multiple data server sessions at once if necessary.
The instrument classes behave similar to the one from the old toolkit. But now they by default automatically expose all available nodes from the device. Meaning if the firmware updates and provides new nodes, users can, without the need of an update, also use these nodes in zhinst-qcodes immediately. The naming of the nodes in zhinst-qcodes is identical to LabOne, making it easy to find the correct nodes or applying examples form LabOne to QCoDeS.
Since the old zhinst-qcodes hardcoded the available nodes and also used custom names for them code written for the old zhinst-qcodes will not work any longer, at least not without replacing the node names. The list below lists all the old node names and their correct successors.
zhinst-qcodes also forwards all helper functions from zhinst-toolkit. During the refactoring the name of these functions where normalized and the content was refactored. The list below lists all the old functions and their their correct successors.
Device specific changes:
Automatic sequencer code generation#
A big part of the old zhinst-qcodes/-toolkit was the automatic sequence and waveform generation for a predefined set of applications. Although these predefined sets may give a easy entry point they where not suited for real measurements. We decided to remove these and instead offer an easy way of uploading sequencer code, waveforms and command table instead. Check out the examples of LabOne and zhinst-toolkit to see predefined sequencer code.