> For the complete documentation index, see [llms.txt](https://docs.yudash.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yudash.com/dc/df/modbus-tcp-ip.md).

# Modbus TCP/IP

YuDash LYNX supports Modbus TCP/IP to read various PLC/HMIs through ethernet. In principle, following are the pre-requesites for using Modbus TCP/IP:

1. Valid Ethernet settings of YuDash LYNX for communication over TCP/IP.
2. LYNX is Modbus Client, who request the data. The given PLC is Modbus server, who will provide the data. LYNX can read multiple Modbus TCP/IP servers.
3. Following details of a given Modbus Server (PLC) are required for communication:

* **IP address** of PLC. For example: ***192.168.1.100***
* **IP Port** on which Modbus server is running. For example: ***502*** (standard port). Or ***8888*** (any port being used by PLC)
* **Modbus Server ID** as per protocol. For example: ***1*** (The Server ID of Modbus is similar to slave ID of Modbus RS-485)
* **Modbus Registers and Data Types** The mapping of registers and selection procedure is similar to Modbus RS-485

There are different network topology possible for interfacing PLC/HMI with LYNX using Modbus TCP/IP. For example:

#### A) Peer to Peer Direct Connection 

<figure><img src="/files/KGuJSLJxu4lan2rylKb2" alt=""><figcaption></figcaption></figure>

#### B) Through Ethernet Switch&#x20;

<figure><img src="/files/1rGfsRB95VfNhd8c43Va" alt=""><figcaption></figcaption></figure>

#### C) Through LAN Router with Static IP

<figure><img src="/files/enywDwRycV7flZwcwpg1" alt=""><figcaption></figcaption></figure>

#### &#x20;D) Through LAN Router with Dynamic IP

<figure><img src="/files/wS8LpsIT4xeqXWF5VhcR" alt=""><figcaption></figcaption></figure>

All the scenarios of Modbus TCP/IP are covered in the video below.

{% embed url="<https://youtu.be/nYAulkX165c>" %}