Graphical program which executes a timed loop

• US 20050050515A1
• Filed: 07/16/2004
• Published: 03/03/2005
• Est. Priority Date: 08/07/2003
• Status: Active Grant

• Current Assignee: National Instruments Corporation (Emerson Electric Company)
• Original Assignee: National Instruments Corporation (Emerson Electric Company)
• Inventors: Vrancic, Aljosa, Kodosky, Jeffrey L., Kornerup, Jacob, Shah, Biren, Santori, Michael L.
• Granted Patent: US 7,574,690 B2
• Time in Patent Office: Days
• US Class Current: 717/113
• CPC Class Codes: G06F 11/323 Visualisation of programs or trace data
• CPC Class Codes: G06F 8/34 Graphical or visual programming

Abstract

A system and method for creating a graphical program operable to execute a timed loop. A loop may be displayed in the graphical program and configured with timing information in response to user input. The timing information may include an execution period which specifies a desired period at which the loop should execute during execution of the graphical program. The timing information may also include information such as a timing source, offset, and priority. During execution of the graphical program, the execution period of the loop may control the rate at which the loop executes.

Claims

1. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first priority;

wherein the first loop is operable to execute according to the first execution period and the first priority during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

2. The carrier medium of claim 1,

wherein the graphical program comprises a data flow graphical program.

3. The carrier medium of claim 1,

wherein the first loop has a graphical appearance to visually indicate its functionality.

4. The carrier medium of claim 1,

wherein the first loop is operable to iterate multiple times;

wherein said first loop executing according to the first execution period comprises each iteration of the first loop executing according to the first execution period and the first priority.

5. The carrier medium of claim 1,

wherein the first loop is operable to iterate multiple times;

wherein said first loop executing according to the first execution period comprises each iteration of the first loop beginning execution at times defined by the first execution period.

6. The carrier medium of claim 1,

wherein the first loop is operable to iterate multiple times;

wherein said first loop executing according to the first execution period comprises successive iterations of the first loop beginning execution at times separated by the first execution period.

7. The carrier medium of claim 1,

wherein said displaying the plurality of nodes in response to user input comprises displaying one or more of the nodes such that they are associated with the first loop;

wherein said first loop executing according to the first execution period and the first priority during execution of the graphical program comprises the one or more nodes associated with the first loop executing according to the first execution period and the first priority during execution of the graphical program;

wherein the one or more nodes associated with the first loop visually indicate functionality performed by the first loop.

8. The carrier medium of claim 7,

wherein the first loop is operable to perform multiple iterations during execution of the graphical program;

wherein the one or more nodes associated with the first loop are executed in each iteration of the first loop;

wherein, for each iteration, the one or more nodes associated with the first loop begin execution at a time determined by the first execution period.

9. The carrier medium of claim 7,

wherein said displaying one or more of the nodes such that they are associated with the first loop comprises displaying the one or more nodes within the first loop;

wherein said displaying the one or more nodes within the first loop visually indicates that the one or more nodes are executed in each iteration of the first loop.

10. The carrier medium of claim 1, further comprising program instructions operable to:

display a graphical user interface for configuring the first loop with timing information;

wherein said configuring the first loop with the first timing information in response to user input comprises configuring the first loop with information specified by user input to the graphical user interface, wherein the user input to the graphical user interface specifies the first execution period and the first priority.

11. The carrier medium of claim 1,

wherein said configuring the first loop with the first execution period and the first priority comprises connecting one or more wires to one or more terminals in the graphical program in response to user input, wherein the one or more wires specify the first execution period and the first priority.

12. The carrier medium of claim 11,

wherein the one or more terminals in the graphical program comprise one or more terminals associated with the first loop.

13. The carrier medium of claim 1,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first timing source, wherein the first execution period is based on the first timing source.

14. The carrier medium of claim 13,

wherein the first execution period comprises a specified number of ticks of the first timing source.

15. The carrier medium of claim 13,

wherein the first execution period comprises a specified number of events generated by the first timing source.

16. The carrier medium of claim 13,

wherein the first timing source comprises one of:

a system clock provided by a computer system;

a clock provided by a hardware board coupled to a computer system.

17. The carrier medium of claim 13,

wherein the first timing source comprises one of:

an analog input/analog output (AI/AO) port of a hardware device;

a counter (CTR) port of a hardware device;

a digital IO (DIO) port of a hardware device.

18. The carrier medium of claim 1,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first offset;

wherein the first loop is operable to iterate multiple times;

wherein iterations of the first loop begin executing at times defined by the first execution period and the first offset.

19. The carrier medium of claim 1,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first timeout;

wherein the first loop is operable to wake up if the first timeout expires between iterations of the first loop.

20. The carrier medium of claim 19,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first timing source, wherein the first execution period is based on the first timing source;

wherein the first timeout is based on a timing source other than the first timing source.

21. The carrier medium of claim 1, further comprising program instructions operable to:

configure the graphical program to dynamically change the first timing information for the first loop during execution of the graphical program, in response to user input.

22. The carrier medium of claim 21,

wherein said configuring the graphical program to dynamically change the first timing information for the first loop comprises one or more of:

configuring the graphical program to dynamically change the first execution period of the first loop during execution of the graphical program;

configuring the graphical program to dynamically change the first priority of the first loop during execution of the graphical program; and

/or

configuring the graphical program to dynamically change an offset of the first loop during execution of the graphical program.

23. The carrier medium of claim 21,

wherein one or more terminals for dynamically changing the first timing information for the first loop are associated with the first loop;

wherein said configuring the graphical program to dynamically change the first timing information for the first loop comprises connecting one or more wires to the one or more terminals in response to user input.

24. The carrier medium of claim 1, further comprising program instructions operable to:

configure one or more nodes associated with the first loop to receive information regarding a previous iteration of the first loop during execution of the graphical program, in response to user input.

25. The carrier medium of claim 24,

wherein one or more terminals for dynamically receiving information regarding a previous iteration of the first loop are associated with the first loop;

wherein said configuring the one or more nodes to receive the information comprises connecting the one or more nodes to the one or more terminals in response to user input.

26. The carrier medium of claim 1, further comprising program instructions operable to:

execute the graphical program;

wherein said executing the graphical program comprises executing the first loop according to the first execution period and the first priority.

27. The carrier medium of claim 26,

wherein said executing the first loop comprises executing one or more nodes associated with the first loop for multiple iterations;

wherein said executing the first loop according to the first execution period comprises scheduling execution of the iterations to begin at times determined by the first execution period.

28. The carrier medium of claim 26, further comprising program instructions operable to:

dynamically re-configure the first loop with new timing information during execution of the graphical program.

29. The carrier medium of claim 28,

wherein said dynamically re-configuring the first loop with new timing information comprises one or more of:

changing the execution period of the first loop;

changing the priority of the first loop; and

/or

changing an offset of the loop.

30. The carrier medium of claim 1, further comprising program instructions operable to:

display information on a block diagram of the graphical program to visually indicate at least a portion of the first timing information for the first loop.

31. The carrier medium of claim 30,

wherein said displaying information on the block diagram of the graphical program to visually indicate at least a portion of the first timing information for the first loop comprises displaying information on the block diagram of the graphical program to visually indicate that the first loop is configured to execute according to the first execution period and the first priority.

32. The carrier medium of claim 1,

wherein said displaying the plurality of nodes in response to user input comprises displaying a first subset of the nodes such that they are associated with the first loop and a second subset of the nodes such that they are not associated with the first loop;

wherein said first loop executing according to the first priority comprises the first subset of nodes executing according to the first priority;

wherein the second subset of nodes execute according to a second priority;

wherein the first priority is a higher priority than the second priority.

33. The carrier medium of claim 1,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first late mode;

wherein the first late mode specifies desired behavior of the first loop in response to iterations of the first loop that occur late.

34. The carrier medium of claim 33,

wherein the first late mode specifies whether the first loop should process data from missed iterations.

35. The carrier medium of claim 33,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first offset;

wherein the first late mode specifies whether execution timing of the first loop should be aligned with a schedule defined by the first execution period and the first offset.

36. The carrier medium of claim 1, wherein the program instructions are further executable to:

display a second loop in the graphical program in response to user input; and

configure the second loop with second timing information in response to user input, wherein said configuring the second loop with second timing information includes configuring the second loop with a second execution period and a second priority;

wherein the second loop is operable to execute according to the second execution period and the second priority during execution of the graphical program.

37. The carrier medium of claim 36,

wherein the second execution period for the second loop is different than the first execution period for the first loop.

38. The carrier medium of claim 36,

wherein the second priority for the second loop is different than the first priority for the first loop.

39. The carrier medium of claim 38,

wherein the second priority is a higher priority than the first priority;

wherein execution of the second loop preempts execution of the first loop during execution of the graphical program.

40. The carrier medium of claim 36,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first offset;

wherein the first loop is operable to iterate multiple times;

wherein iterations of the first loop begin executing at times defined by the first execution period and the first offset;

wherein said configuring the second loop with the second timing information also includes configuring the second loop with a second offset;

wherein the second loop is operable to iterate multiple times;

wherein iterations of the second loop begin executing at times defined by the second execution period and the second offset.

41. The carrier medium of claim 40,

wherein the second offset for the second loop is different than the first offset for the first loop.

42. The carrier medium of claim 36,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first timing source, wherein the first execution period is based on the first timing source;

wherein said configuring the second loop with the second timing information also includes configuring the second loop with a second timing source, wherein the second execution period is based on the second timing source.

43. The carrier medium of claim 42,

wherein the first timing source is the same as the second timing source.

44. The carrier medium of claim 42,

wherein the first timing source is different than the second timing source.

45. The carrier medium of claim 36,

wherein the first execution period is the same as the second execution period;

wherein execution timing of iterations of the first loop is aligned with execution timing of iterations of the second loop.

46. The carrier medium of claim 45,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first offset;

wherein said configuring the second loop with the second timing information also includes configuring the second loop with a second offset;

wherein the first offset is different than the second offset;

wherein iterations of the first loop begin executing at times defined by the first execution period and the first offset;

wherein iterations of the second loop begin executing at times defined by the second execution period and the second offset;

wherein iterations of the first loop and iterations of the second loop are performed at a single rate but with different offsets with respect to a timing source.

47. The carrier medium of claim 45,

wherein each iteration of the first loop is operable to produce data;

wherein each iteration of the second loop is operable to consume data produced by a corresponding iteration of the first loop.

48. The carrier medium of claim 1,

wherein said first loop executing according to the first execution period and the first priority during execution of the graphical program enables the first loop to execute in alignment with timing of a first hardware device.

49. The carrier medium of claim 1, further comprising program instructions operable to:

execute the graphical program;

wherein said executing the graphical program comprises executing a plurality of iterations of the first loop;

wherein each iteration of the first loop is passed a reason indicating why the iteration began executing.

50. The carrier medium of claim 49,

wherein said executing the plurality of iterations of the first loop comprises executing a first iteration of the first loop;

wherein the first iteration of the first loop is passed a first reason indicating why the first iteration began executing;

wherein the first reason indicates that the first iteration began executing because of one of the following reasons;

the first iteration began executing normally at a time when the first iteration was scheduled to begin execution;

the first iteration began executing because the first loop was programmatically aborted;

the first iteration began executing because a timeout associated with the first loop expired.

108. The carrier medium of claim 1, further comprising program instructions operable to:

execute the graphical program;

wherein one or more events associated with the loop are generated during execution of the graphical program;

wherein each iteration of the loop executes in response to an event associated with the loop being generated.

51. A carrier medium comprising a graphical program, wherein the graphical program includes:

a plurality of interconnected nodes; and

a first loop;

wherein the first loop is configured with first timing information, wherein the first timing information includes a first execution period and a first priority;

wherein the first loop is operable to execute according to the first execution period and the first priority during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

52. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first offset;

wherein the first loop is operable to execute according to the first execution period and the first offset during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

53. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first timing source and a first execution period, wherein the first execution period is based on the first timing source;

wherein the first loop is operable to execute according to the first execution period during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

54. The carrier medium of claim 53,

wherein the first execution period comprises a specified number of ticks of the first timing source.

55. The carrier medium of claim 53,

wherein the first execution period comprises a specified number of events generated by the first timing source.

56. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first timeout;

wherein the first loop is operable to execute according to the first execution period during execution of the graphical program, wherein said first loop executing according to the first execution period comprises iterations of the first loop beginning execution at times defined by the first execution period;

wherein the first loop is operable to wake up if the first timeout expires between iterations of the first loop;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

57. The carrier medium of claim 56,

wherein said configuring the first loop with the first timing information also includes configuring the first loop with a first timing source, wherein the first execution period is based on the first timing source;

wherein the first timeout is based on a timing source other than the first timing source.

58. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first deadline;

wherein the first loop is operable to execute according to the first execution period during execution of the graphical program, wherein said first loop executing according to the first execution period comprises iterations of the first loop beginning execution at times defined by the first execution period;

wherein, for each iteration of the first loop, the first deadline defines a time by which the iteration must complete execution or else be considered late;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

59. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period;

wherein the first loop is operable to execute according to the first execution period during execution of the graphical program;

wherein the plurality of interconnected nodes includes a first node operable to cause execution of the first loop to abort when the first node is executed during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

60. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a first loop in the graphical program in response to user input;

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period; and

display first graphical source code associated with the first loop in the graphical program in response to user input;

wherein the first graphical source code associated with the first loop includes a second loop such that the second loop is nested within the first loop;

wherein the program instructions are further executable to;

configure the second loop with second timing information in response to user input, wherein said configuring the second loop with second timing information includes configuring the second loop with a second execution period; and

display second graphical source code associated with the second loop in the graphical program in response to user input.

61. The carrier medium of claim 60,

wherein the first loop is operable to execute according to the first execution period during execution of the graphical program, wherein said first loop executing according to the first execution period comprises a plurality of iterations of the first loop executing according to the first execution period;

wherein, during each iteration of the first loop, the second loop is operable to execute according to the second execution period, wherein said second loop executing according to the second execution period comprises a plurality of iterations of the second loop executing according to the second execution period.

62. A method for creating a graphical program, the method comprising:

displaying a plurality of nodes in the graphical program in response to user input;

interconnecting the plurality of nodes in response to user input;

displaying a first loop in the graphical program in response to user input; and

configuring the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first priority;

wherein the first loop is operable to execute according to the first execution period and the first priority during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

63. A system for creating a graphical program, the system comprising:

a processor; and

a memory medium storing program instructions;

wherein the processor is operable to execute the program instructions to;

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first priority;

wherein the first loop is operable to execute according to the first execution period and the first priority during execution of the graphical program;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.

64. A carrier medium comprising program instructions operable to:

display a loop in a graphical program in response to user input;

associate one or more nodes with the loop, wherein the one or more nodes visually indicate functionality performed by the loop; and

configure the loop with timing information, wherein said configuring the loop with timing information includes configuring the loop with an execution period and an offset;

wherein the loop is operable to perform multiple iterations during execution of the graphical program, wherein each iteration begins execution at a time determined by the execution period and the offset.

65. The carrier medium of claim 64,

wherein the one or more nodes associated with the loop are executed at each iteration of the loop.

66. The carrier medium of claim 65,

wherein, for each iteration, the one or more nodes associated with the loop begin execution at a time determined by the execution period.

67. A carrier medium comprising program instructions operable to:

display a plurality of nodes in a graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

wherein the plurality of nodes are interconnected to visually indicate functionality of the graphical program;

wherein the plurality of interconnected nodes include one or more nodes operable to periodically perform first functionality;

wherein the carrier medium further comprises program instructions operable to;

receive user input specifying timing information, wherein the timing information includes an execution period and a priority; and

configure the one or more nodes to periodically perform the first functionality at times determined by the execution period and the priority.

68. The carrier medium of claim 67,

wherein the one or more nodes operable to periodically perform the first functionality comprises a first sub-program node, wherein the first sub-program node is operable to perform the first functionality, wherein the first sub-program node is configured to periodically execute at times determined by the execution period and the priority.

69. The carrier medium of claim 67,

wherein the one or more nodes operable to periodically perform the first functionality comprise one or more nodes performed in a loop;

wherein iterations of the loop are performed at times determined by the execution period and the priority.

70. A carrier medium comprising program instructions operable to:

display a first loop in a graphical program in response to user input;

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period;

display a second loop in the graphical program in response to user input; and

configure the second loop with second timing information in response to user input, wherein said configuring the second loop with second timing information includes configuring the second loop with a second execution period;

wherein, during execution of the graphical program, the first loop is timed to execute according to the first execution period and the second loop is timed to execute according to the second execution period.

71. The carrier medium of claim 70,

wherein the first loop and the second loop execute concurrently.

72. The carrier medium of claim 70,

wherein the first loop is operable to iterate multiple times;

wherein the second loop is operable to iterate multiple times;

wherein said first loop executing according to the first execution period comprises each iteration of the first loop beginning execution at times defined by the first execution period;

wherein said second loop executing according to the second execution period comprises each iteration of the second loop beginning execution at times defined by the second execution period.

73. The carrier medium of claim 70,

wherein the first execution period is different than the second execution period.

74. The carrier medium of claim 70,

wherein the first execution period and the second execution period are based on a common timing source.

75. The carrier medium of claim 70,

wherein the first execution period and the second execution period are based on different timing sources.

76. The carrier medium of claim 70,

wherein said configuring the first loop with first timing information also includes configuring the first loop with a first priority;

wherein said configuring the second loop with second timing information also includes configuring the second loop with a second priority;

wherein, during execution of the graphical program, the first loop executes at the first priority and the second loop executes at the second priority.

77. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input, wherein the plurality of nodes comprise a loop node;

associate at least a subset of the plurality of nodes with the loop node, wherein the loop node indicates looping of the at least a subset of the plurality of nodes;

display interconnections between the plurality of nodes in response to user input; and

configure the loop node with timing information in response to user input, wherein said configuring the loop node with timing information includes configuring the loop node with an execution period;

wherein the loop node is operable to execute according to the execution period during execution of the graphical program;

wherein the plurality of interconnected nodes visually indicate functionality of the graphical program, wherein the graphical program implements a model of a system.

78. A carrier medium comprising program instructions operable to:

include a loop in a graphical program in response to user input; and

associate one or more events with the loop;

wherein the loop is operable to execute for a plurality of iterations, wherein each iteration executes in response to an event from the one or more events associated with the loop.

79. The carrier medium of claim 78,

wherein said associating the one or more events with the loop comprises associating a timing source with the loop, wherein the one or more events are associated with the timing source.

80. The carrier medium of claim 78, wherein the program instructions are further operable to:

configure the loop with an execution period, wherein the execution period specifies a number N;

wherein each iteration executing in response to an event comprises each iteration executing in response to an Nth event being generated.

81. The carrier medium of claim 78,

wherein the graphical program comprises a plurality of interconnected nodes that visually indicate functionality of the graphical program.

82. The carrier medium of claim 81, further comprising program instructions operable to:

arrange the plurality of nodes on a display; and

interconnect the plurality of nodes in response to user input.

83. The carrier medium of claim 78,

wherein the graphical program comprises a graphical data flow program.

84. The carrier medium of claim 78,

wherein the loop has a graphical appearance to visually indicate its functionality.

85. The carrier medium of claim 78, further comprising program instructions operable to:

associate graphical source code with the loop in response to user input;

wherein said loop executing for the plurality of iterations comprises the graphical source code associated with the loop executing for the plurality of iterations.

86. The carrier medium of claim 85,

wherein said associating the graphical source code with the loop comprises associating one or more nodes with the loop, wherein the one or more nodes visually indicate functionality performed by the loop.

87. The carrier medium of claim 85,

wherein said associating the graphical source code with the loop comprises positioning the graphical source code within the loop.

88. The carrier medium of claim 78,

wherein said each iteration of the loop executing in response to an event from the one or more events associated with the loop comprises each iteration of the loop executing in response to an event from the one or more events associated with the loop being generated during execution of the graphical program.

89. The carrier medium of claim 78,

wherein said associating the one or more events with the loop comprises associating the one or more events with the loop before execution of the graphical program.

90. The carrier medium of claim 89, further comprising program instructions operable to:

display a graphical user interface for specifying event information for the loop; and

receive user input to the graphical user interface to associate the one or more events with the loop.

91. The carrier medium of claim 90,

wherein the graphical user interface displays one or more timing sources;

wherein said receiving user input to the graphical user interface to associate the one or more events with the loop comprises receiving user input to the graphical user interface to select a timing source for the loop, wherein the one or more events comprise events generated by the timing source.

92. The carrier medium of claim 90,

wherein the graphical user interface displays a plurality of events;

wherein said receiving user input to the graphical user interface comprises receiving user input to select the one or more events from the plurality of events.

93. The carrier medium of claim 78,

wherein said associating the one or more events with the loop comprises dynamically associating the one or more events with the loop during execution of the graphical program.

94. The carrier medium of claim 93,

wherein the graphical program includes one or more nodes operable to dynamically associate the one or more events with the loop during execution of the graphical program.

95. The carrier medium of claim 94, further comprising program instructions operable to:

configure a first node to associate the one or more events with the loop, wherein said configuring the first node comprises connecting one or more wires to the first node, wherein the one or more wires represent the one or more events to associate with the loop.

96. The carrier medium of claim 78,

wherein the one or more events associated with the loop include a first event associated with a first hardware device;

wherein the loop is operable to iterate in response to the first event being generated by the first hardware device during execution of the graphical program.

97. The carrier medium of claim 96,

wherein the loop is configured to iterate in response to each Nth event generated by the first hardware device during execution of the graphical program, wherein N is a positive integer.

98. The carrier medium of claim 78,

wherein the one or more events associated with the loop include a first event associated with a first data acquisition device;

wherein the loop is operable to iterate in response to the first event being generated by the first data acquisition device during execution of the graphical program.

99. The carrier medium of claim 78,

wherein the one or more events associated with the loop include one or more hardware-generated events.

100. The carrier medium of claim 78,

wherein the one or more events associated with the loop include one or more software-generated events.

101. The carrier medium of claim 78, wherein the one or more events associated with the loop include one or more of:

a user interface event;

a system event;

a timer event.

102. The carrier medium of claim 78, wherein the one or more events associated with the loop include one or more network events.

103. The carrier medium of claim 102, wherein the one or more network events include one or more of:

an event indicating arrival of network data;

an event indicating that a network buffer is full.

104. The carrier medium of claim 78,

wherein the one or more events associated with the loop include a first event from a source external to the graphical program;

wherein the loop iterates in response to the first event being generated externally to the graphical program during execution of the graphical program.

105. The carrier medium of claim 104,

wherein the graphical program is executed by a graphical program execution engine;

and

wherein the first event is generated externally to the graphical program execution engine.

106. The carrier medium of claim 104,

wherein the graphical program is created using a graphical programming development environment;

wherein the first event comprises an event from a source external to the graphical programming development environment.

107. The method of claim 78,

wherein the graphical program is operable to execute the loop to perform one or more of:

an industrial automation function;

a process control function;

a test and measurement function; and

/or

a simulation function.

109. A carrier medium comprising program instructions for creating a graphical program, wherein the program instructions are executable to:

display a plurality of nodes in the graphical program in response to user input;

interconnect the plurality of nodes in response to user input;

display a first loop in the graphical program in response to user input; and

configure the first loop with first timing information in response to user input, wherein said configuring the first loop with first timing information includes configuring the first loop with a first execution period and a first late mode;

wherein the first loop is operable to execute according to the first execution period during execution of the graphical program;

wherein the first late mode specifies desired behavior of the first loop in response to iterations of the first loop that occur late;

wherein the plurality of interconnected nodes and the first loop visually indicate functionality of the graphical program.