hvl_ccb.dev.visa

class VisaDevice(com: Union[VisaCommunication, VisaCommunicationConfig, dict], dev_config: Optional[Union[VisaDeviceConfig, dict]] = None)

Bases: SingleCommDevice

Device communicating over the VISA protocol using VisaCommunication.

static config_cls()

Return the default configdataclass class.

Returns

a reference to the default configdataclass class

static default_com_cls() → Type[VisaCommunication]

Return the default communication protocol for this device type, which is VisaCommunication.

Returns

the VisaCommunication class

get_error_queue() → str

Read out error queue and logs the error.

Returns

Error string

get_identification() → str

Queries “*IDN?” and returns the identification string of the connected device.

Returns

the identification string of the connected device

reset() → None

Send “*RST” and “*CLS” to the device. Typically sets a defined state.

spoll_handler()

Reads the status byte and decodes it. The status byte STB is defined in IEEE 488.2. It provides a rough overview of the instrument status.

Returns

start() → None

Start the VisaDevice. Sets up the status poller and starts it.

Returns

stop() → None

Stop the VisaDevice. Stops the polling thread and closes the communication protocol.

Returns

wait_operation_complete(timeout: Optional[float] = None) → bool

Waits for a operation complete event. Returns after timeout [s] has expired or the operation complete event has been caught.

Parameters

timeout – Time in seconds to wait for the event; None for no timeout.

Returns

True, if OPC event is caught, False if timeout expired

class VisaDeviceConfig(spoll_interval: Union[int, float] = 0.5, spoll_start_delay: Union[int, float] = 2)

Bases: _VisaDeviceConfigDefaultsBase, _VisaDeviceConfigBase

Configdataclass for a VISA device.

force_value(fieldname, value)

Forces a value to a dataclass field despite the class being frozen.

NOTE: you can define post_force_value method with same signature as this method to do extra processing after value has been forced on fieldname.

Parameters

• fieldname – name of the field

• value – value to assign

classmethod keys() → Sequence[str]

Returns a list of all configdataclass fields key-names.

Returns

a list of strings containing all keys.

classmethod optional_defaults() → Dict[str, object]

Returns a list of all configdataclass fields, that have a default value assigned and may be optionally specified on instantiation.

Returns

a list of strings containing all optional keys.

classmethod required_keys() → Sequence[str]

Returns a list of all configdataclass fields, that have no default value assigned and need to be specified on instantiation.

Returns

a list of strings containing all required keys.