---
title: "Wiring"
description: "Complete wiring guide for TapHome smart home system. RS-485 bus, Modbus RTU connections, topology recommendations, and surge protection."
url: "https://taphome.com/en/docs/wiring/"
language: en
lastmod: 2023-01-01
generator: hugo
ai:
  topics: ["wiring","rs-485-bus","modbus-rtu","bus-topology","surge-protection","optical-isolation"]
  questions: ["What bus topologies can I use with TapHome modules?","What is the maximum number of modules on one TapHome bus?","What cables are recommended for TapHome RS-485 bus wiring?","What termination resistor value should I use?","When do I need surge protection for the RS-485 bus?","When should I use optical bus isolation?","Why is ring topology prohibited for TapHome buses?"]
---

# Wiring

Last updated: 2023-01-01

**See also** — [Serial Bus Topology](https://taphome.com/en/docs/wiring/serial-bus-topology/), [Modbus RTU Wiring Examples](https://taphome.com/en/docs/wiring/modbus-wiring/), [Surge Protection](https://taphome.com/en/docs/wiring/surge-protection/).

- [Serial Bus Topology](https://taphome.com/en/docs/wiring/serial-bus-topology/) — Method of connecting components in different types of buses - linear, tree, star, and ring topology. Recommendations for the correct connection of TapHome modules.
- [Bus Extender — Wiring and Bus Termination](https://taphome.com/en/docs/wiring/bus-extender/) — Bus 1–4 ports on the Bus Extender, when to use a galvanically isolated port, where the 100 Ω termination resistor goes depending on the topology, and four wiring diagrams.
- [Optical Bus Isolation](https://taphome.com/en/docs/wiring/optical-isolation/) — Galvanic separation of RS-485 and Modbus buses with a bidirectional optical isolator. Basic ESD protection on the SLAVE side; the SLAVE side needs its own power supply.
- [Surge Protection](https://taphome.com/en/docs/wiring/surge-protection/) — Essential surge protection for RS-485 and Modbus buses in exterior areas. Includes protection for power supplies and current loops. Prevents voltage damage with multi-stage circuits.
- [PWM converter for a 0–10 V output signal](https://taphome.com/en/docs/wiring/pwm-converter/) — PWM-to-0–10 V signal converter for centralized lighting control in larger spaces and industrial facilities. Powered from the same 24 V DC power supply as the TapHome modules, with simple calibration.
- [Modbus RTU Wiring Examples](https://taphome.com/en/docs/wiring/modbus-wiring/) — Rules and examples for connecting devices to the Modbus RTU line with TapHome control system. Information about wiring, addressing, and communication parameters.
- [CT Clamp — Current Measurement via Analog Input](https://taphome.com/en/docs/wiring/ct-clamp-analog-input/) — How to connect a CT clamp (current transformer) with 0-10V output to TapHome universal input for continuous current measurement.