PyJEM.femtus.acquisition¶

Acquisition service API .

Todo

Prerequisites:: The Scan Area is configured in the UI.

>>> from PyJEM.femtus import acquisition
>>> acquisition.get_detectors()
{'Detectors': ['EDS', 'EELS', 'Image']}
>>> acquisition.get_status()
{
    'Status': {
        'AcquisitionID': '00000000-0000-0000-0000-000000000000',
        'AcquisitionRunning': True,
        'SweepCount': 2,
        'ElapsedSeconds': 61293.0765006
        },
    Version': '1.0.0'
}
>>> result = acquisition.get_settings()
>>> setting = result["Settings"][0]
>>> setting["Detectors"] = ["Image"]
>>> setting["Region"]["Width"] = 128
>>> setting["Region"]["Height"] = 128
>>> setting["Conditions"]["DwellTime"] = 100
>>> start(setting)
{
    'AcquisitionID': '00000000-0000-0000-0000-000000000000',
    'WorksheetID': '00000000-0000-0000-0000-000000000000',
    'ReferenceDetector': '',
    'Version': '1.0.0'
}
>>> stop()
{'Result': 'OK', 'Version': '1.0.0'}

PyJEM.femtus.acquisition.get_detectors()¶

Retrieve the list of detectors.

Returns:

The returned value is a dictionary. A description of each item is provided below.

key	type	value
Detectors	list[str]	List of available detector names. Example: `["EDS", "EELS", "Image"]`
Version	str	API version string.

key

type

value

Detectors

list[str]

List of available detector names.

Example:: ["EDS", "EELS", "Image"]

Version

str

API version string.

Return type:

dict

Examples

>>> get_detectors()
{
    "Detectors": [
        "EDS",
        "EELS",
        "Image"
    ],
    "Version": "1.0.0"
}

PyJEM.femtus.acquisition.get_status()¶

Retrieve the current acquisition status and version information.

Returns:

The returned value is a dictionary. A description of each item is provided below.

key

type

value

Version

str

API version string.

Status

dict

Acquisition status object with the following fields

⇒ See Status items.

Status items

key	type	value
AcquisitionRunning	bool	`True` if acquisition is currently running.
AcquisitionID	str	Unique identifier of the current or last acquisition.
SweepCount	int \| float	Number of completed sweeps.
ElapsedSeconds	float	Elapsed time since acquisition start, in seconds.

Return type:

dict

Examples

>>> get_status()
{
    "Version": "1.0.0",
    "Status": {
        "AcquisitionRunning": False,
        "AcquisitionID": "00000000-0000-0000-0000-000000000000",
        "SweepCount": 1,
        "ElapsedSeconds": 100
    }
}

PyJEM.femtus.acquisition.get_settings()¶

Retrieve acquisition settings as json object. You cannot retrieve the conditions unless they are configured in the FEMTUS UI.

Returns:

The returned value is a dictionary. A description of each item is provided below

key	type	value
Version	str	API version string.
Settings	list[dict]	List of Settings items.

Settings items

key	type	value
Id	str	Data acquisition settings identifier.
Detectors	list[str]	A list of detectors that can perform data acquisition; configurable detectors can be obtained using GetAvailableDetectors.
Region	dict	The area information indicating the data acquisition range will cause an error if it specifies an area outside the image size range. The image size follows the Scan settings at runtime. ⇒ See Region items.
Conditions	dict	Data Acquisition Conditions ⇒ See Conditions items.
DriftCorrection	dict	Dictionary specifying drift correction parameters. ⇒ See DriftCorrection items.

Region items

key	type	value
Left	int	X coordinate of top-left corner in pixels.
Top	int	Y coordinate of top-left corner in pixels.
Width	int	Width of acquisition region in pixels.
Height	int	Height of acquisition region in pixels.
Shape	str	One of `"Point"`, `"Line"`, `"Rectangle"`. Default is `"Rectangle"`.

Conditions items

key	type	value
DwellTime	int	Exposure time in microseconds. If omitted, current scan setting is used. Attention: The minimum DwellTime value is determined by the configured detector; values below this will result in an error.
CollectionMode	dict	Data acquisition mode. ⇒ See CollectionMode items.
PixelResolution	float	One of `0.25`, `0.5`, `1`, `2`, `4`. Default is `1.0`.
IsPlayback	bool	If `True`, save data as time-series without accumulation.

CollectionMode items

key	type	value
Mode	str	Mode kind are `"Sweep"`, `"Time"`, `"Endless"`. `Sweep` Executes the scan a specified number of times. Requires `value` to be the number of sweeps. `Time` Executes the scan for the specified duration. Requires `value` to be the acquisition time in seconds. `Endless` Executes the scan continuously until `Stop` is called. `value` is ignored.
Count	int	The semantics of the output values differ depending on the selected mode. `Mode=="Sweep"` Number of scans performed `Mode=="Time"` Data acquisition execution time, unit: [seconds] `Mode=="Endless"` Not set.

key

type

value

Mode

str

Mode kind are "Sweep", "Time", "Endless".

Sweep
Executes the scan a specified number of times. Requires value to be the number of sweeps.
Time
Executes the scan for the specified duration. Requires value to be the acquisition time in seconds.
Endless
Executes the scan continuously until Stop is called. value is ignored.

Count

int

The semantics of the output values differ depending on the selected mode.

Mode=="Sweep"
Number of scans performed
Mode=="Time"
Data acquisition execution time, unit: [seconds]
Mode=="Endless"
Not set.

DriftCorrection items

key	type	value
Type	str	One of `"None"`, `"Line"`, `"Seconds"`, `"Frames"`, `"LossLess"`. `"LossLess"`: only valid when the image size matches the correction region. `"None"`: disables drift correction.
Interval	int	Correction interval. Unit depends on `Type`. `"Line"` : every N lines `"Seconds"` : every N seconds `"Frames"` : every N frames `"LossLess"` : every N frames
CorrectionRegion	dict	Region within the image used for drift correction. If omitted, the entire image is used. All coordinates are in pixels. ⇒ See CorrectionRegion items.

key

type

value

Type

str

One of "None", "Line", "Seconds", "Frames", "LossLess".

"LossLess": only valid when the image size matches the correction region.
"None": disables drift correction.

Interval

int

Correction interval. Unit depends on Type.

"Line" : every N lines
"Seconds" : every N seconds
"Frames" : every N frames
"LossLess" : every N frames

CorrectionRegion

dict

Region within the image used for drift correction. If omitted, the entire image is used. All coordinates are in pixels.

⇒ See CorrectionRegion items.

CorrectionRegion items

key	type	value
Left	int	X coordinate of top-left corner (>= 0).
Top	int	Y coordinate of top-left corner (>= 0).
Width	int	Width of correction region (power of 2 recommended).
Height	int	Height of correction region (power of 2 recommended).

Return type:

dict

Examples

>>> get_settings()
{
    "Settings": [
        {
            "Conditions": {
                "CollectionMode": {
                    "Count": 1,
                    "Mode": "Sweep"
                },
                "DwellTime": 1,
                "IsPlayback": False,
                "PixelResolution": 1
            },
            "Detectors": [],
            "DriftCorrection": {
                "CorrectionRegion": None,
                "Interval": 1,
                "Type": "None"
            },
            "Id": "56896236-c55b-4354-b8a5-bf238efc4d18",
            "Region": {
                "Height": 512,
                "Left": 0,
                "Points": None,
                "Shape": "Rectangle",
                "Top": 0,
                "Width": 512
            }
        }
    ],
    "Version": "1.0.0"
}

PyJEM.femtus.acquisition.get_acquisition_result(id)¶

Retrieve the acquisition result for a specific detector.

Parameters:

id (str) –

Unique identifier for the acquisition result. Must be a valid GUID string.

Example:: "00000000-0000-0000-0000-000000000000".

Returns:

The returned value is a dictionary. A description of each item is provided below.

key	type	value
Version	str	API version string.
Results	list[dict]	List of Results items.

Results items

key	type	value
Id	str	Identifier of result data.
DataType	str	Data type/format identifier. See `DataType(FormatID).xlsx`.

Return type:

dict

Examples

>>> get_acquisition_result("detector_id")
{
    "Results": [
        {
            "DataType": "STEM_Survey",
            "Id": "03aa06db-95ba-4330-82e3-8ba940775f2f"
        },
        {
            "DataType": "STEM_HAADF_SeleArea",
            "Id": "969a5682-4614-4c2b-b9df-dbbfd11185f7"
        }
    ]
}

PyJEM.femtus.acquisition.start(param)¶

Start the acquisition service.

Parameters:

param (dict) –

Acquisition settings payload.

key	type	value
Detectors	list[str]	Detector names used for acquisition.
Region	dict	See Region items.
Conditions	dict	See Conditions items.
DriftCorrection	dict	See DriftCorrection items.

Returns:

JSON response for the start request.

key	type	value
Version	str	API version string.
AcquisitionID	str	Unique identifier of the acquisition result.
WorksheetID	str	Identifier of the worksheet where the result is stored.
ReferenceDetector	str	Name of the reference detector for the acquisition settings.

Return type:

dict

Examples

>>> param = {
        "Conditions": {
            "CollectionMode": {
                "Count": 1,
                "Mode": "Sweep"
            },
            "DwellTime": 1,
            "IsPlayback": False,
            "PixelResolution": 1
        },
        "Detectors": [
            "Image"
        ],
        "DriftCorrection": {
            "CorrectionRegion": None,
            "Interval": 1,
            "Type": "None"
        },
        "Region": {
            "Height": 512,
            "Left": 0,
            "Points": None,
            "Shape": "Rectangle",
            "Top": 0,
            "Width": 512
        }
    }
>>> start(param)
{
    "AcquisitionID": "40d1a2a5-4bfb-4841-8be5-b99c5395eef2",
    "ReferenceDetector": "",
    "Version": "1.0.0",
    "WorksheetID": "a4fef4e1-90d9-4334-bedf-671b575e2db4"
}

PyJEM.femtus.acquisition.stop()¶

Stop the currently running data acquisition. When running in EndlessMode, data acquisition will not complete until this request is sent

Returns:

JSON response for the stop request.

key	type	value
Version	str	API version string.
Result	str	Execution status. One of `"OK"` or `"Fail"`.

Return type:

dict

Examples

>>> stop()
{'Result': 'OK', 'Version': '1.0.0'}