# 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>" %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.yudash.com/yudash-iot-devices/lynx-user-manual/lynx-settings/modbus-tcp-ip.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.