Programming Reference:GenericADC Class - Revision history

Mellinger: Programming Reference:GenericADC moved to Programming Reference:GenericADC Class

2008-04-07T16:49:27Z

Programming Reference:GenericADC moved to Programming Reference:GenericADC Class

← Older revision		Revision as of 16:49, 7 April 2008
(No difference)

Mellinger: /* Purely Virtual `Halt` */

2008-04-07T15:13:27Z

Purely Virtual <tt>Halt</tt>

← Older revision		Revision as of 15:13, 7 April 2008
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	==Purely Virtual <tt>Halt</tt>==		==Purely Virtual <tt>Halt</tt>==
	Unlike <tt>GenericFilter</tt>, the <tt>Halt</tt> member function is declared purely virtual in <tt>GenericADC</tt>~~, implying~~ that a derived class ''must'' provide its own implementation of <tt>Halt</tt>, even if that implementation is empty.		Unlike <tt>GenericFilter</tt>, the <tt>Halt</tt> member function is declared "purely virtual" in <tt>GenericADC</tt>.
			This implies that a derived class ''must'' provide its own implementation of <tt>Halt</tt>, even if that implementation may be empty.

	This is to stress the importance of a proper implementation of <tt>Halt</tt> for smooth system operation.		This is to stress the importance of a proper implementation of <tt>Halt</tt> for smooth system operation.
	More often than not, a source module will rely on asynchronous activity in a hardware driver, or a separate data acquisition thread maintained by the <tt>GenericADC</tt> descendant itself. Such asynchronous activity must be halted from the <tt>Halt</tt> function in order to ensure proper behavior of the source module at reconfiguration and shutdown time.		More often than not, a source module will rely on asynchronous activity in a hardware driver, or a separate data acquisition thread maintained by the <tt>GenericADC</tt> descendant itself. Such asynchronous activity must be halted from the <tt>Halt</tt> function in order to ensure proper behavior of the source module at reconfiguration and shutdown time.

Mellinger at 15:11, 7 April 2008

2008-04-07T15:11:46Z

New page

The <tt>GenericADC</tt> class is a base class for data acquisition components.
Its main purpose is to provide a common ancestor for these components, to make them identifiable at run-time using run-time-type-information (RTTI).
Thus, it forwards the [[Programming Reference:GenericFilter Class|GenericFilter]] class interface, except for the following changes:

==Purely Virtual <tt>Halt</tt>==
Unlike <tt>GenericFilter</tt>, the <tt>Halt</tt> member function is declared purely virtual in <tt>GenericADC</tt>, implying that a derived class ''must'' provide its own implementation of <tt>Halt</tt>, even if that implementation is empty.
This is to stress the importance of a proper implementation of <tt>Halt</tt> for smooth system operation.
More often than not, a source module will rely on asynchronous activity in a hardware driver, or a separate data acquisition thread maintained by the <tt>GenericADC</tt> descendant itself. Such asynchronous activity must be halted from the <tt>Halt</tt> function in order to ensure proper behavior of the source module at reconfiguration and shutdown time.

==Empty Output==
For <tt>GenericADC</tt> descendants, the output signal's dimensions should be specified as "empty" in the <tt>Preflight</tt> function.

==See also==
[[Programming Tutorial:Implementing a Data Acquisition Module]], [[Programming Reference:GenericFilter Class]]

[[Category:Framework API]] [[Category:Development]]

Programming Reference:GenericADC Class - Revision history

Mellinger: Programming Reference:GenericADC moved to Programming Reference:GenericADC Class

Mellinger: /* Purely Virtual Halt */

Mellinger at 15:11, 7 April 2008

Mellinger: /* Purely Virtual `Halt` */