lewis.devices.chopper.interfaces.epics_interface

Members

ChopperEpicsInterface

ESS chopper EPICS interface
class lewis.devices.chopper.interfaces.epics_interface.ChopperEpicsInterface[source]

Bases: EpicsInterface

ESS chopper EPICS interface

Interaction with this interface should happen via ChannelAccess (CA). The PV-names usually carry a prefix which depends on the concrete device and environment, so it is omitted in this description. The dynamically generated description of the PVs does however contain the prefix so that the names can be copy-pasted easily.

The first step is to initialize the chopper, for example via caput on the command line:

$ caput CmdS init

After this, the chopper is in a state where it can be started:

$ caget State State stopped

To set a specific speed and phase, the setpoints have to be configured via caput:

$ caput Spd 100 $ caput Phs 34.5

Then the chopper can be commanded to move towards those values:

$ caput CmdS start

Now the disc accelerates to the setpoints, the state should now be different:

$ caget State State accelerating

The possible commands are part of the PV-specific documentation.

property execute_command: str

Command to execute. Possible commands are start, stop, set_phase, unlock, park, init, deinit.

property last_command

The last command that was executed successfully.