---
tags: notes, RT_blog, node red, modbus
---

# Node-Red: Modbus Client(Master)
> The all in one Modbus TCP and Serial contribution package for Node-RED.
> Based on [modbus-serial](https://www.npmjs.com/package/modbus-serial) with TCP, C701, Telnet, Serial, RTU buffered, and ASCII
> stress tested with Node-RED v1.0.4 and Node.js LTS
>
> From official introduction

**node-red-contrib-modbus**: [node-red page](https://flows.nodered.org/node/node-red-contrib-modbus), [github page](https://github.com/biancoroyal/node-red-contrib-modbus), [npm page](https://www.npmjs.com/package/node-red-contrib-modbus)

To continue with this note, I guess you have Node-Red installed, you know what Modbus is and how to build a simulation modbus server. If you don't, check the links bellow:
- [Node-Red: Getting Started](/2lIjZeA_RvaLDSyLX4mhtA)
- [Modbus: Simple Introduction]
- [Modbus TCP Server Simulation Tools](/@pR_YkvzoQK-kLPlR_gXGAg/Sky-T64ND)

## Install modbus nodes
You can consider node-red-contrib-modbus is a plugin, an extension, a module or an library. Here we are going to install it so we can use modbus nodes.
I can't install it with `npm` as the [official suggested](https://github.com/biancoroyal/node-red-contrib-modbus#install), so I'm gonna show you how to install it with web page GUI.

Firt thing first, open the node-red web server:

node-red

And then go to `localhost:1880/` with a web browser. Remember to change `localhost` to target IP and change `1880` to a specific port if you start Node-Red with the option `--port`. The following operations are all in the web page.

1. Click `≡` at the right upper corner
2. Click `Manage palette`
3. Click `Install`
4. Type `modbus`
5. Install `node-red-contrib-modbus`
6. Click `Install` in the popping message
7. If nothing goes wrong, you should see nodes of modbus at the left palette
8. If you don't see any modbus node after installation, you may want to restart Node-Red web server, refresh the page and check it again.