Technical Reference:Core Modules - Revision history

Mellinger: /* State Vector Storage */

2022-03-04T12:48:36Z

State Vector Storage

← Older revision		Revision as of 12:48, 4 March 2022
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	For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.		For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.
	Note that the ''SourceTime'' state is an exception insofar as it matches the acquisition time of the current block.		Note that the ''SourceTime'' state is an exception insofar as it matches the acquisition time of the current block.
			As a result, the ''StimulusTime'' state (and similar states) will always have a smaller value than the ''SourceTime'' state, and needs to be referenced to the ''SourceTime'' state of the previous block in order to obtain processing delay.

	==Signal Processing Module==		==Signal Processing Module==

Mellinger: /* State Vector Storage */

2022-03-04T12:46:01Z

State Vector Storage

← Older revision		Revision as of 12:46, 4 March 2022
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	===State Vector Storage===		===State Vector Storage===
	For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.		For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.
			Note that the ''SourceTime'' state is an exception insofar as it matches the acquisition time of the current block.

	==Signal Processing Module==		==Signal Processing Module==

Mellinger: /* Application Module */

2008-10-24T15:50:13Z

Application Module

← Older revision		Revision as of 15:50, 24 October 2008
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	completely encapsulate each module and separate it from others.		completely encapsulate each module and separate it from others.
	In order to minimize inter-dependence, duties should be performed by the module that is conceptually defining the feature. For example, task paradigm and timing are, conceptually, parts of a task and should therefore be handled by the user application module.		In order to minimize inter-dependence, duties should be performed by the module that is conceptually defining the feature. For example, task paradigm and timing are, conceptually, parts of a task and should therefore be handled by the user application module.
	[[User Reference:CursorTask]] an implementation of a such a user task - a simple cursor task - that complies with the idea of minimal inter-dependence.		[[User Reference:CursorTask]] is an implementation of a such a user task - a simple cursor task - that complies with the idea of minimal inter-dependence.

	==See also==		==See also==

Mellinger: /* Signal Processing Module */

2008-10-18T15:07:46Z

Signal Processing Module

← Older revision		Revision as of 15:07, 18 October 2008
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	==Signal Processing Module==		==Signal Processing Module==
	~~===Overview===~~		Signal Processing acts like a black box to the rest of the system - it receives brain signals from the Signal Source and sends control signals on to the Application.
	Signal Processing acts like a black box to the rest of the system - it receives ~~EEG~~ signals from the ~~Data Acquisition~~ and sends control signals on to the Application.

	The data flow in a typical implementation is as follows:		The data flow in a typical implementation is as follows:
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	For each input block of data, there must be a resulting output block.		For each input block of data, there must be a resulting output block.

	==~~=Goals=~~==		==Module Independence==
	One of the goals for BCI2000 is for each module to be as independent of the others as possible.		One of the goals for BCI2000 is for each module to be as independent of the others as possible.
	For example, Signal Processing should not have to take the type of data collection		For example, Signal Processing should not have to take the type of data collection
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	Application can be minimized.		Application can be minimized.

	===Assumptions and Dependencies===		==Assumptions and Dependencies==
	~~Signal Processing~~ can contain instances of multiple filter classes.		BCI2000 core modules can contain instances of multiple filter classes.
	These filter		These filter classes cannot assume any specific values for system-wide parameters such as
	classes cannot assume any specific values for
	''SampleBlockSize'',		''SampleBlockSize'',
	''SamplingRate'', or ''TransmitCh''. ~~They~~ have to be able to		''SamplingRate'', or ''TransmitCh''. Rather, they have to be able to
	adapt their functionality according to these three parameters -- they might		adapt their functionality according to these three parameters -- they might
	not only be used in scenarios with varying parameters, but they might also have		not only be used in scenarios with varying parameters, but they might also have
	to work together with other filters. Therefore, hard coded assumptions about		to work together with other filters. Therefore, hard coded assumptions about
	~~these three~~ parameters have to be avoided.		system-wide parameters have to be avoided.

	==Application Module==		==Application Module==

Mellinger: /* State Vector Storage */

2008-10-18T15:04:05Z

State Vector Storage

← Older revision		Revision as of 15:04, 18 October 2008
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	===State Vector Storage===		===State Vector Storage===
	~~''Note:''~~ For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.		For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.

	==Signal Processing Module==		==Signal Processing Module==

Mellinger: /* Signal Source Module */

2008-10-18T15:03:54Z

Signal Source Module

← Older revision		Revision as of 15:03, 18 October 2008
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	.dat		.dat
	format, together with the raw digitized data.		format, together with the raw digitized data.

			===Data Acquisition and Storage Loop===
	During normal operation (''Running'' is 1), the Signal Source module		During normal operation (''Running'' is 1), the Signal Source module
	runs in a data acquisition loop that ~~basically reads~~		runs a data acquisition and storage loop that has the following structure:
	<pre>		<pre>
	1: While Running		1: While Running
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	6: Save A/D data to file		6: Save A/D data to file
	</pre>		</pre>
	Note that statement 3 as well as statement 5 are blocking operations,
	i.e.,		===Real-Time Constraint===
	the module will wait for A/D data as well as for the state vector data		Note that statement 3 as well as statement 5 are blocking operations, i.e., the module will wait for A/D data as well as for the state vector data
	coming in from the Application module.		coming in from the Application module.
	This mode of operation requires a sufficiently fast system to work		This mode of operation imposes a real-time constraint on signal processing, and therefore requires a "sufficiently fast" system to work properly.
	properly.		For our purposes, a "sufficiently fast" system is a system where
	For our purposes, a "fast" system is a system where

	*synchronous I/O operations (2, 4, 5, and 6) require an execution time that is small compared to the duration of a data block (as given by the sampling rate and the sample block size), and		*synchronous I/O operations (2, 4, 5, and 6) require an execution time that is small compared to the duration of a data block (as given by the sampling rate and the sample block size), and
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	statements will reduce the waiting interval occurring in statement 3.		statements will reduce the waiting interval occurring in statement 3.

			===State Vector Storage===
	''Note:'' For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.		''Note:'' For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.

Mellinger: /* Signal Source Module */

2008-10-18T14:18:42Z

Signal Source Module

← Older revision		Revision as of 14:18, 18 October 2008
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	==Signal Source Module==		==Signal Source Module==
	The role of the ~~Brain~~ Signal Source module is to wait for data		The role of the Signal Source module is to wait for data
	blocks		blocks
	coming in from the A/D hardware, and to send these blocks of data on		coming in from the A/D hardware, and to send these blocks of data on
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	.dat		.dat
	format, together with the raw digitized data.		format, together with the raw digitized data.
	During normal operation (''Running'' is 1), the ~~EEG source~~ module		During normal operation (''Running'' is 1), the Signal Source module
	runs in a data acquisition loop that basically reads		runs in a data acquisition loop that basically reads
	<pre>		<pre>

Mellinger: /* Data Acquisition Module */

2008-10-18T14:17:48Z

Data Acquisition Module

← Older revision		Revision as of 14:17, 18 October 2008
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	Between core modules, data flow in a closed loop, clocked by data acquisition hardware.		Between core modules, data flow in a closed loop, clocked by data acquisition hardware.

	==~~Data Acquisition~~ Module==		==Signal Source Module==
	The role of the ~~EEG Data Acquisition (or~~ Source) module is to wait for data		The role of the Brain Signal Source module is to wait for data
	blocks		blocks
	coming in from the A/D hardware, and to send these blocks of data on		coming in from the A/D hardware, and to send these blocks of data on

Mellinger: /* Data Acquisition Module */

2008-03-25T10:13:01Z

Data Acquisition Module

← Older revision		Revision as of 10:13, 25 March 2008
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	statements will reduce the waiting interval occurring in statement 3.		statements will reduce the waiting interval occurring in statement 3.

	''Note:'' For the data in the file, ~~the above pseudocode implies that~~ the state vector which results from processing a ~~packet~~ <math>n</math> is saved together with the following ~~packet~~, <math>n+1</math>.		''Note:'' For the data in the file, the state vector which results from processing a data block <math>n</math> is saved together with the following block, <math>n+1</math>. For the first block, a state vector is saved that contains initial values.

	==Signal Processing Module==		==Signal Processing Module==

Mellinger: /* Data Acquisition Module */

2008-03-25T10:04:25Z

Data Acquisition Module

← Older revision		Revision as of 10:04, 25 March 2008
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	remaining		remaining
	statements will reduce the waiting interval occurring in statement 3.		statements will reduce the waiting interval occurring in statement 3.

			''Note:'' For the data in the file, the above pseudocode implies that the state vector which results from processing a packet <math>n</math> is saved together with the following packet, <math>n+1</math>.

	==Signal Processing Module==		==Signal Processing Module==