LabVIEW Program and Data Flow Review LabVIEW Robotics Fundamentals

Data Flow Many code objects in LabVIEW generate data – Constants always put out one “constant” value – Read Sensor commands send out sensor values – Operations like “Divide” send out result values Data flows through wires Value = 75 Value = Sound Sensor Reading Value = Ultrasonic Sensor Reading divided by 2

Data Flow Data is used by commands and Structures Motor power set to 75 Motor power set to Sound Sensor value Motor power set to Sound Sensor value divided by 2

Data Flow Data is used by commands and Structures Repeats 8 times If Touch Sensor is Pressed, run this “True” pane code Repeats until Port C Rotations exceed 1800 degrees

Front Panel Data The Front Panel can provide and display data – Controls generate values that can be used in code – Indicators display values in different ways

Data Flow Every command in LabVIEW runs as soon as all its “incoming” data is ready The NXT Pink Wire is actually just a creative use of Data Flow to create sequences of commands that have to wait for one another

Data Flow: Parallelism Every command in LabVIEW runs as soon as all its “incoming” data is ready – This even lets multiple code strands run at once!

Controlling Program Flow Structures can control when commands run – Sequence Structures force groups of commands to run in a certain order

Controlling Program Flow Structures can control when commands run – Case Structures choose alternative sets of code to run, based on an input value

Controlling Program Flow Structures can control when commands run – For Loops repeat code a set number of times

Controlling Program Flow Structures can control when commands run – While Loops repeat code until a wired Stop condition is reached

Control Loops Control Loops are a strategic arrangement of a Case and a Loop – Repeats a decision quickly so it looks “continuous”

Shift Registers Shift Registers pass values across loop cycles – This allows values to “accumulate” or “count up”