> For the complete documentation index, see [llms.txt](https://inscada.gitbook.io/ins/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://inscada.gitbook.io/ins/en-1/communication-protocols/modbus/modbus-tcp-server.md).

# Modbus TCP Server

Modbus TCP Server is a protocol used by the Master/Client that responds to queries received by the device. The ability to use this protocol in the inSCADA side provides a great deal of flexibility. inSCADA now gets a similar role as devices with the help of the protocol.

![Figure 1 : Modbus TCP Server ](https://3585470428-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLGnZudlzfM63QD-_cp%2F-LknDfJkOw1PKT8OfIDr%2F-LknGY7ugXVikboYOCVS%2Fmodbustcpserver.png?alt=media\&token=a5adea88-5ee0-48a9-b54a-d5e21199cb59)

As shown in Figure 1, inSCADA can now share data with other devices on the network using this protocol.

{% hint style="info" %}
Let's remember the Value Expression property of inSCADA. With the Modbus TCP Server protocol, you can make a simulator of any device in inSCADA using the value expression.
{% endhint %}

{% hint style="info" %}
You do not need to create virtual/internal variables in the inSCADA platform as you would do in any other SCADA software. If this is the case, you simply need to create a device using Modbus TCP Server protocol. It also has a much more powerful structure to hold data in memory in the inSCADA platform. See [getGlobalObject ](https://inscada.gitbook.io/ins/v/en-1/programing/apis/getglobalobject)and [setGlobalObject](https://inscada.gitbook.io/ins/v/en-1/programing/apis/setglobalobject).
{% endhint %}