mpylab.device.multichannel_common module

Device-independent infrastructure for shared multi-channel drivers.

class mpylab.device.multichannel_common.SharedController

Bases: object

Own one transport and register facades for one physical device.

attach(client)

Register one facade and reject duplicate physical channels.

Parameters:

client (SharedFacade) – Logical channel facade to register.

Raises:

RuntimeError – If another facade already represents the same physical channel.

close()

Close the physical transport once.

invalidate_snapshot()

Discard a synchronized acquisition snapshot.

read_by_acquisition_policy(channel, read_independent, read_synchronized)

Read one channel according to the configured acquisition policy.

In synchronized mode, one callback result is retained as a shared snapshot until every requested channel has consumed its entry.

Parameters:

• channel (int) – One-based physical channel number.

• read_independent (callable) – Zero-argument callback that reads only the requested channel.

• read_synchronized (callable) – Zero-argument callback that reads all channels into an indexable snapshot.

Returns:

Value returned for the requested channel.

Return type:

object

Raises:

RuntimeError – If the configured acquisition policy is unsupported.

release(client)

Detach a facade and close the transport after the final client.

Parameters:

client (SharedFacade) – Logical channel facade to detach.

Returns:

True if this was the final facade and the transport was closed.

Return type:

bool

trigger()

Start a new logical synchronized acquisition generation.

Returns:

Zero after invalidating the previous shared snapshot.

Return type:

int

class mpylab.device.multichannel_common.SharedFacade

Bases: object

Common lifecycle for logical facades sharing one controller.

GetDescription()

Return the configured and physical instrument descriptions.

Returns:

Status code and combined description string.

Return type:

tuple of (int, str)

Quit()

Release this facade and eventually close the shared transport.

Returns:

Zero on success.

Return type:

int

classmethod reset_controllers()

Close and remove all shared controllers of this driver class.

mpylab.device.multichannel_common.parse_acquisition(value, device_name, supported=frozenset({'independent', 'synchronized'}))

Normalize an acquisition policy and reject unsupported modes.

Parameters:

• value (str or None) – Requested acquisition policy. A missing value selects independent.

• device_name (str) – Device name used in validation errors.

• supported (collection of str, optional) – Acquisition policies supported by the concrete device.

Returns:

Normalized acquisition policy.

Return type:

str

Raises:

ValueError – If the policy is unknown or unsupported by the device.

mpylab.device.multichannel_common.retrigger_requested(value)

Normalize the boolean-like retrigger argument used by GetDataNB.

Parameters:

value (bool, str, or None) – Boolean value or a common textual ON/OFF representation.

Returns:

Normalized retrigger decision.

Return type:

bool

Raises:

ValueError – If value is not a recognized boolean representation.