User Reference:SignalSharing - Revision history

Mellinger: /* See also */

2026-03-12T15:35:42Z

Mellinger: /* Client Examples */

2026-03-11T14:50:47Z

Client Examples

← Older revision		Revision as of 14:50, 11 March 2026
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	==Client Examples==		==Client Examples==
	* An example for a ''SignalSharing'' client application in C++ using the [[Technical Reference:SignalSharingClient Library\|SignalSharingClient Library]]: [[Programming Reference:SignalSharingClientLibDemo\|SignalSharingClientLibDemo]]		* An example for a ''SignalSharing'' client application in C++ using the [[Technical Reference:SignalSharingClient Library\|SignalSharingClient Library]]: [[Programming Reference:SignalSharingClientLibDemo\|SignalSharingClientLibDemo]]
	* An example for a ''SignalSharing'' client application in C++: [[Programming_Reference:SignalSharingDemoClient C%2B%2B App\|SignalSharingDemoClient C++ App]]		* An example for a ''SignalSharing'' client application in C++ using the BCI2000 C++ framework: [[Programming_Reference:SignalSharingDemoClient C%2B%2B App\|SignalSharingDemoClient C++ App]]
	* An example for a ''SignalSharing'' client application in Python: [[Programming_Reference:SignalSharing_Python_Demo\|SignalSharing Python Demo]]		* An example for a ''SignalSharing'' client application in Python: [[Programming_Reference:SignalSharing_Python_Demo\|SignalSharing Python Demo]]

Mellinger: /* Client Examples */

2026-03-11T14:50:05Z

Client Examples

← Older revision		Revision as of 14:50, 11 March 2026
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	==Client Examples==		==Client Examples==
	* An example for a ''SignalSharing'' client application in C++ using the [[Technical Reference:SignalSharingClient Library\|SignalSharingClient Library]]: Programming Reference:SignalSharingClientLibDemo\|SignalSharingClientLibDemo]]		* An example for a ''SignalSharing'' client application in C++ using the [[Technical Reference:SignalSharingClient Library\|SignalSharingClient Library]]: [[Programming Reference:SignalSharingClientLibDemo\|SignalSharingClientLibDemo]]
	* An example for a ''SignalSharing'' client application in C++: [[Programming_Reference:SignalSharingDemoClient C%2B%2B App\|SignalSharingDemoClient C++ App]]		* An example for a ''SignalSharing'' client application in C++: [[Programming_Reference:SignalSharingDemoClient C%2B%2B App\|SignalSharingDemoClient C++ App]]
	* An example for a ''SignalSharing'' client application in Python: [[Programming_Reference:SignalSharing_Python_Demo\|SignalSharing Python Demo]]		* An example for a ''SignalSharing'' client application in Python: [[Programming_Reference:SignalSharing_Python_Demo\|SignalSharing Python Demo]]

Mellinger: /* Client Examples */

2026-03-11T14:49:44Z

Client Examples

← Older revision		Revision as of 14:49, 11 March 2026
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	==Client Examples==		==Client Examples==
			* An example for a ''SignalSharing'' client application in C++ using the [[Technical Reference:SignalSharingClient Library\|SignalSharingClient Library]]: Programming Reference:SignalSharingClientLibDemo\|SignalSharingClientLibDemo]]
	* An example for a ''SignalSharing'' client application in C++: [[Programming_Reference:SignalSharingDemoClient C%2B%2B App\|SignalSharingDemoClient C++ App]]		* An example for a ''SignalSharing'' client application in C++: [[Programming_Reference:SignalSharingDemoClient C%2B%2B App\|SignalSharingDemoClient C++ App]]
	* An example for a ''SignalSharing'' client application in Python: [[Programming_Reference:SignalSharing_Python_Demo\|SignalSharing Python Demo]]		* An example for a ''SignalSharing'' client application in Python: [[Programming_Reference:SignalSharing_Python_Demo\|SignalSharing Python Demo]]

Mellinger: /* See also */

2026-03-11T14:46:44Z

Mellinger: /* Data Transmission */

2026-03-05T14:38:30Z

Data Transmission

← Older revision		Revision as of 14:38, 5 March 2026
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	Immediately after opening the connection, ''SignalSharing'' sends a number of [[Technical_Reference:BCI2000_Messages#Descriptor=2:_Parameter_Format\|Parameter]] messages to share the parameters that are present in the system. The client may choose to ignore them, or use them for its own purposes.		Immediately after opening the connection, ''SignalSharing'' sends a number of [[Technical_Reference:BCI2000_Messages#Descriptor=2:_Parameter_Format\|Parameter]] messages to share the parameters that are present in the system. The client may choose to ignore them, or use them for its own purposes.

	Following parameter messages, ''SignalSharing'' sends a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message to announce meta-information about the filter's output signal, such as channel names, physical units, etc. The <tt>sourceID</tt> field of the signal properties message equals the string "Signal".		Following those parameter messages, ''SignalSharing'' sends a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message to announce meta-information about the filter's output signal, such as channel names, physical units, etc. The <tt>sourceID</tt> field of the signal properties message equals the string "Signal".

	If configured to send state information, ''SignalSharing'' will send another [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message conveying meta-information about a signal that accommodates state information. This message's <tt>sourceID</tt> field will equal the string "States".		If configured to send state information, ''SignalSharing'' will send another [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message conveying meta-information about a signal that accommodates state information. This message's <tt>sourceID</tt> field will equal the string "States".

Mellinger: /* Data Transmission */

2025-06-25T15:37:28Z

Data Transmission

← Older revision		Revision as of 15:37, 25 June 2025
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	Signal data contains a flag that indicates whether full signal data is sent, or just the name of a shared memory block. For local connections (i.e., connections to a local address of the machine BCI2000 is running on), the name of a shared memory block is sent, so you may attach to that block and read data from there. Between two subsequent times the user presses "Set Config" in the Operator interface, the shared memory block will remain the same, i.e. the signal data message will always contain the same shared memory name. Still, the message is necessary to indicate that a new data block is available.		Signal data contains a flag that indicates whether full signal data is sent, or just the name of a shared memory block. For local connections (i.e., connections to a local address of the machine BCI2000 is running on), the name of a shared memory block is sent, so you may attach to that block and read data from there. Between two subsequent times the user presses "Set Config" in the Operator interface, the shared memory block will remain the same, i.e. the signal data message will always contain the same shared memory name. Still, the message is necessary to indicate that a new data block is available.

	If configured to so, ''SignalSharing'' will follow each brain signal data message with another signal message which holds state information. The state information message is a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=1:_Signal_Data\|signal data]] message in which individual states correspond to channels, and state samples correspond to elements. This signal data's <tt>sourceID</tt> field will contain the string "States".		A signal message contains the specification of a number format, i.e. one of <tt>int16</tt>, <tt>int32</tt>, or <tt>float32</tt>. If transmitted through a channel such as a TCP connection, the signal's binary representation will be a sequence of numbers according to the number format. In shared memory, however, signal representation is '''always IEEE 754 64-bit double format'''.

			If configured to do so, ''SignalSharing'' will follow each brain signal data message with another signal message which holds state information. The state information message is a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=1:_Signal_Data\|signal data]] message in which individual states correspond to channels, and state samples correspond to elements. This signal data's <tt>sourceID</tt> field will contain the string "States".

	Depending on position in the signal processing chain, the number of state samples may differ from the number of signal samples/elements because the number of state samples will always be identical to brain signal source block size, whereas the number of signal samples/elements depends on the position in the chain.		Depending on position in the signal processing chain, the number of state samples may differ from the number of signal samples/elements because the number of state samples will always be identical to brain signal source block size, whereas the number of signal samples/elements depends on the position in the chain.

Wengelhardt at 18:45, 9 January 2025

2025-01-09T18:45:47Z

← Older revision		Revision as of 18:45, 9 January 2025
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	==Synopsis==		==Synopsis==
	''SignalSharing'' allows to ~~tap~~ into BCI2000 processing by receiving any filter output signal through a combination of a TCP connection, and shared memory.		''SignalSharing'' uniquely allows for '''''asynchronous processing'''''. Data can be received and sent outside of the standard [[User Reference:Filters\|BCI2000 pipeline]] (at any point in the filter chain!), allowing for timescales independent of the BCI2000 block-wise processing. This is useful for applications such as [[Python Visualizations\|real-time visualization]], or signal processing algorithms that take a substantial amount of time to compute an output.

			''SignalSharing'' taps into the BCI2000 processing pipeline by receiving any filter output signal through a combination of a TCP connection, and shared memory.
	In addition, signal and state data may be modified from the client side, i.e. they may be injected into BCI2000.		In addition, signal and state data may be modified from the client side, i.e. they may be injected into BCI2000.

Mellinger: /* Back Channel */

2024-10-22T18:38:56Z

Back Channel

← Older revision		Revision as of 18:38, 22 October 2024
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	==Back Channel==		==Back Channel==
	''SignalSharing'' allows to send signal data as well as state data back to BCI2000. Signal data must have the same dimensions as the signal received through ''SignalSharing'', and is sent as a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=1:_Signal_Data\|signal data]] message.		''SignalSharing'' allows to send signal data as well as state data back to BCI2000. Signal data must have the same dimensions as the signal received through ''SignalSharing'', and is sent as a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=1:_Signal_Data\|signal data]] message.
	Similarly, state data is sent as a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=0:_Original_State_Format\|state]] message. In this state message, ~~the~~ Length, ByteLocation, and BitLocation fields are ignored; only ~~the~~ Name and Value fields are used.		Similarly, state data is sent as a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=0:_Original_State_Format\|state]] message. In this state message, Length, ByteLocation, and BitLocation fields are ignored; only Name and Value fields are used.

	To allow for synchronization between signal and state changes received from the client, no action is taken until another message is received. That message is a special [[Technical_Reference:BCI2000_Messages#Descriptor=6:_System_Command\|system command]] message with content ''EndOfData''. Once this message has been received, signal and state changes will be applied the next time the shared filter's data have been updated inside the BCI2000 processing chain.		To allow for synchronization between signal and state changes received from the client, no action is taken until another message is received. That message is a special [[Technical_Reference:BCI2000_Messages#Descriptor=6:_System_Command\|system command]] message with content ''EndOfData''. Once this message has been received, signal and state changes will be applied the next time the shared filter's data have been updated inside the BCI2000 processing chain.

Mellinger: /* Data Transmission */

2024-10-22T18:37:27Z

Data Transmission

← Older revision		Revision as of 18:37, 22 October 2024
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	Depending on position in the signal processing chain, the number of state samples may differ from the number of signal samples/elements because the number of state samples will always be identical to brain signal source block size, whereas the number of signal samples/elements depends on the position in the chain.		Depending on position in the signal processing chain, the number of state samples may differ from the number of signal samples/elements because the number of state samples will always be identical to brain signal source block size, whereas the number of signal samples/elements depends on the position in the chain.

			==Back Channel==
			''SignalSharing'' allows to send signal data as well as state data back to BCI2000. Signal data must have the same dimensions as the signal received through ''SignalSharing'', and is sent as a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=1:_Signal_Data\|signal data]] message.
			Similarly, state data is sent as a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=0:_Original_State_Format\|state]] message. In this state message, the Length, ByteLocation, and BitLocation fields are ignored; only the Name and Value fields are used.

			To allow for synchronization between signal and state changes received from the client, no action is taken until another message is received. That message is a special [[Technical_Reference:BCI2000_Messages#Descriptor=6:_System_Command\|system command]] message with content ''EndOfData''. Once this message has been received, signal and state changes will be applied the next time the shared filter's data have been updated inside the BCI2000 processing chain.

	==Configuration==		==Configuration==

← Older revision		Revision as of 15:35, 12 March 2026
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	[[Programming Reference:GenericSignal Class]],		[[Programming Reference:GenericSignal Class]],
	[[Technical Reference:SignalSharingClient Library]],		[[Technical Reference:SignalSharingClient Library]],
			[[Programming Reference:SignalSharingClientLibDemo]]
	[[Programming Reference:SignalSharingDemoClient C++ App]],		[[Programming Reference:SignalSharingDemoClient C++ App]],
	[[Programming Reference:~~SignalSharing Python Demo\|~~SignalSharing Python Demo]]		[[Programming Reference:SignalSharing Python Demo]]

	[[Category:Framework API]]		[[Category:Framework API]]
	[[Category:External Interfaces]]		[[Category:External Interfaces]]

← Older revision		Revision as of 14:46, 11 March 2026
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	[[Technical Reference:BCI2000 Messages]], [[User Tutorial:BCI2000Remote]],		[[Technical Reference:BCI2000 Messages]], [[User Tutorial:BCI2000Remote]],
	[[Programming Reference:GenericSignal Class]],		[[Programming Reference:GenericSignal Class]],
			[[Technical Reference:SignalSharingClient Library]],
	[[Programming Reference:SignalSharingDemoClient C++ App]],		[[Programming Reference:SignalSharingDemoClient C++ App]],
	[[Programming Reference:SignalSharing Python Demo\|SignalSharing Python Demo]]		[[Programming Reference:SignalSharing Python Demo\|SignalSharing Python Demo]]

← Older revision		Revision as of 14:38, 5 March 2026
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	Immediately after opening the connection, ''SignalSharing'' sends a number of [[Technical_Reference:BCI2000_Messages#Descriptor=2:_Parameter_Format\|Parameter]] messages to share the parameters that are present in the system. The client may choose to ignore them, or use them for its own purposes.		Immediately after opening the connection, ''SignalSharing'' sends a number of [[Technical_Reference:BCI2000_Messages#Descriptor=2:_Parameter_Format\|Parameter]] messages to share the parameters that are present in the system. The client may choose to ignore them, or use them for its own purposes.

	Following parameter messages, ''SignalSharing'' sends a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message to announce meta-information about the filter's output signal, such as channel names, physical units, etc. The <tt>sourceID</tt> field of the signal properties message equals the string "Signal".		Following those parameter messages, ''SignalSharing'' sends a [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message to announce meta-information about the filter's output signal, such as channel names, physical units, etc. The <tt>sourceID</tt> field of the signal properties message equals the string "Signal".

	If configured to send state information, ''SignalSharing'' will send another [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message conveying meta-information about a signal that accommodates state information. This message's <tt>sourceID</tt> field will equal the string "States".		If configured to send state information, ''SignalSharing'' will send another [[Technical_Reference:BCI2000_Messages#Descriptor_Supplement=3:_Signal_Properties\|SignalProperties]] message conveying meta-information about a signal that accommodates state information. This message's <tt>sourceID</tt> field will equal the string "States".