Industrial Engineer · phase 4 of 16
REAL / Float
Floating-point data type used for fractional values and wide numeric ranges.
The Explain card
- Plain English
- A REAL is a floating point number, one that can carry a fraction and a very wide range. Temperatures, flow rates and scaled engineering values usually live in one.
- Example
- A tank level of twelve and three quarter feet or a flow of four thousandths of a gallon per second both fit in a REAL. An INT could hold neither without scaling tricks.
- Why it matters
- Floats are approximate, so two values that should be equal can differ in the seventh decimal place and a compare for equality fails forever. Use greater than or less than with a small band, and keep money and counts in integers.
- Hook
- Close enough, and never exactly.
Where it sits in the deck
Phase 4: PLC Memory, Tags, and Instructions
The data a program moves and the instructions that move it, from a single true or false value up to a structured array.
