can any one explain me how this diagram works. This diagram shown the measurement of rpm motor in engine by Ne signal
First of all, a screenshot like your attachement only shows a limited section of code, therefore, nobody can tell you what happens in the rest of the code.
You might also consider to get familiar with LV in order to understand the code yourself. There are plenty of tutorials available (e.g. LV in 3 hours).
For starters, read the code following data flow. Each wire has a source and one or multiple sinks.
A function in LV can only execute if all data on inputs provide valid values and once it executed passes on valid values on the outputs. Hence, there is a defined order of execution if functions are wired in series.
The functions should be quite self-explaining like Add or Multiply.
I hope these tips already provide you a basic understanding for this simple code.
EDIT: The blue boxes with numeric values are constants. Nobody can answer the purpose of the constant value though....
that 15M is a scaling factor. You need to look into the manual of your sensor/measuring device what's the reason behind this value is!
You receive 2 bytes (obviously using wrong datatype for those two inputs) which are combined into a 16bit wide value. Then a scaling is done (see manual of sensor) to display the result. Then two comparisons are done (two limits?) and the result is shown in a (picture?) ring…