# Arduino Opta through Modbus TCP

**URL:** <https://community.factoryio.com/t/arduino-opta-through-modbus-tcp/4414>\
**Category:** Support\
**Created:** [November 23, 2025, 9:06pm UTC](https://community.factoryio.com/t/arduino-opta-through-modbus-tcp/4414 "2025-11-23T21:06:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![terrance](https://avatars.discourse-cdn.com/v4/letter/t/53a042/32.png) [@terrance](https://community.factoryio.com/u/terrance)\
**Post date:** [November 23, 2025, 9:06pm UTC](https://community.factoryio.com/t/arduino-opta-through-modbus-tcp/4414/1 "2025-11-23T21:06:27Z")

</div>

I am struggling to see the IO from Factory IO in the Arduino PLC IDE.

I have established connection, but I have wasted hours attempting to see the IO.

This is how the opta addresses modbus IO. (A)

And this is how I have configured Factory IO…. (B)

For some reason I can’t monitor the IO in my PLC IDE from Factory IO.

I would love to purchase a license but i can’t seem to get this to function.

 ![image](https://europe1.discourse-cdn.com/flex017/uploads/factoryio/original/2X/9/9dbbb2189c947c7efe168a7b2f5cb34dec7c2322.png)