# Controlling Brightness on a T50 Mobile Panel (6PMT50.101E-16B) Logically

**URL:** <https://community.br-automation.com/t/controlling-brightness-on-a-t50-mobile-panel-6pmt50-101e-16b-logically/6498>\
**Category:** HMI & Visualization\
**Tags:** t-c-panels\
**Created:** [April 8, 2025, 6:13am UTC](https://community.br-automation.com/t/controlling-brightness-on-a-t50-mobile-panel-6pmt50-101e-16b-logically/6498 "2025-04-08T06:13:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![charlesPonet](https://avatars.discourse-cdn.com/v4/letter/c/FF8800/32.png) [@charlesPonet](https://community.br-automation.com/u/charlesPonet)\
**Post date:** [April 8, 2025, 6:13am UTC](https://community.br-automation.com/t/controlling-brightness-on-a-t50-mobile-panel-6pmt50-101e-16b-logically/6498/1 "2025-04-08T06:13:50Z")

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Hello everyone,

I recently acquired a T50 mobile panel (model number 6PMT50.101E-19B) and I’m looking to control its screen brightness programmatically.

In the user manual, I found a potentially relevant section that mentions controlling brightness using `AsRfbExt`, as shown in the image below:

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/1/13d7026d781c2c8af1c40cc6ebcc14efe94b5282.png)

The reason why this approach is interesting is that I need to be able to dim the panel to lower han 20% brightness.

I have a few questions regarding this:

- From my understanding, `AsRfbExt` interacts with a VNC application. Does this mean that the power panel needs to be actively connected to a VNC server for this method of brightness control to work?
- Has anyone in the community had experience using this `AsRfbExt` library and could offer some guidance or point me towards relevant resources?
- If a VNC connection is required for brightness control via `AsRfbExt`, will I still be able to simultaneously use a web HMI hosted on the PLC’s webserver?

I’ve also come across an example for AsRfbExt using ANSI C, but I find the associated documentation to be somewhat lacking.

My hardware setup includes:

- Panel: 6PMT50.101E-19B
- PLC: X20CP0484

Thank you in advance for any assistance you can provide!

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<div class="post-metadata">

**Author:** ![tommi.piiparinen](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/tommi.piiparinen/32/2183_2.png) [@tommi.piiparinen](https://community.br-automation.com/u/tommi.piiparinen)\
**Post date:** [April 8, 2025, 6:34am UTC](https://community.br-automation.com/t/controlling-brightness-on-a-t50-mobile-panel-6pmt50-101e-16b-logically/6498/2 "2025-04-08T06:34:53Z")

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You can use the OPC UA server functionality on the Power Panel. It has a method **SetBrightnessUnlimited** , which allows to set the screen brightness in the range from 0% to 100%

[Automation Help: Power Panel T50 mobile SetBrightnessUnlimited](https://help.br-automation.com/#/en/6/hardware/powerpanel_mt50/pp_software/setbrightnessunlimited.html)

Examples how to use OPC UA to interact with the panel can be found here:

> **[GitHub - br-automation-community/mappPanel: This is a sample for communication from a B&R PLC...](https://github.com/br-automation-community/mappPanel)**
>
> This is a sample for communication from a B&R PLC to a T-Panel over OPC UA.