“Sequence” (Sıralı) Yapılar

İki farklı sıralı yapı mevcuttur. Tek pencereli (Stacked sequence) Film Şeridi (Flat Sequence) In a text-based language, program statements execute in the order in which they appear. In data flow, a node executes when data is available at all its input terminals. Sometimes it is hard to tell the exact order of execution. Often, certain events must take place before other events. Sequence structure: Used to control the order in which nodes in a diagram will execute. In the Structures subpalette. Looks like a frame of film. Used to execute diagrams sequentially. Like a deck of cards. You can see only one frame at a time. Remind students again that when they see multiple sequence frames, it means to create a single sequence structure, not several.

Data bir pencereden başka pencereye transfer edilebilir You cannot directly wire data from one sequence frame to any another frame with the usual wiring techniques. Sequence locals are variables that pass data between frames of a Sequence structure. Created on the border of the Sequence frame. Data wired to a sequence local is available only in subsequent frames. It is not available in previous frames. In subsequent frames, you can use a sequence local to output only. If you must read a value from a sequence local, change it, and use it in a later frame, you must create another sequence local. Applications for Sequence structures: Benchmarking with DAQ counters (Start Timer, Run Benchmark, Stop Timer). DAQ counters are much more accurate than the timers based on the computer clock. Data available Data not available Sequence local created in Frame 1