WORD

**WORD is a 16-bit unsigned data type** with values from 0 to 65,535 (hex 16#0000 to 16#FFFF). Not to be confused with INT, which is the signed 16-bit equivalent (-32,768 to +32,767).

**Range:** 0 to 65,535 unsigned. No negative values.

**Memory:** exactly 2 bytes (16 bits).

**Common uses:** Modbus holding/input registers (each is 16 bits), status words from drives and instruments, bit-packed flags (16 BOOLs in one variable), small counters, ASCII pairs, indexes for medium-size arrays.

**Syntax across major IDEs:** - Siemens SCL: `myStatus : WORD := 16#0000;` - Studio 5000: Allen-Bradley uses INT (signed) for the same memory; no native unsigned 16-bit - CODESYS / TwinCAT: `myStatus : WORD := 16#0000;`

**Bit access:** address individual bits as `myWord.0` through `myWord.15`. The bit ordering convention is little-endian on Siemens (`bit.0` is the LSB) — verify on your platform.

**Common pitfalls:** assigning a negative number to a WORD (compiler error or wraps depending on IDE); doing arithmetic that overflows 65,535 silently; mixing WORD and INT in expressions without explicit conversion; assuming Modbus register data is signed when WORD is the correct interpretation.

**Conversion:** to INT use `INT_TO_WORD()` / `WORD_TO_INT()` functions. To DINT use intermediate UDINT.

**See also:** INT (signed 16-bit), DWORD (unsigned 32-bit), UINT (unsigned 16-bit on platforms that distinguish).