---
title: "Modbus functions"
canonical: "https://docs.cuesystem.com/space/CVCDD/448135202/Modbus%20functions"
format: markdown
---
The various reading, writing, and other operations are categorized as follows. Prominent entities within a Modbus slave are:

- **Coils**: readable and writable, 1 bit (off/on)
- **Discrete Inputs**: readable, 1 bit (off/on)
- **Input Registers**: readable, 16 bits (0 to 65,535), essentially measurements and statuses
- **Holding Registers**: readable and writable, 16 bits (0 to 65,535), essentially configuration values