receive certain serial data from com port c#

Question

We needed to change the text on aa led panel brought around 7-9 years ago. Hence, long story short, we needed an app for that. The panel has a serial connection. Everything is welded inside a hardcover box. The panel works fine but we need to change the text shown.

Now the thing is, the panel displays temperature taken via a thermometer inside, along with the regular text. I want to receive the text displayed and the temperature, change it in my app then send it back.

Apparently, I can send data after opening serial con as serialPort1.Write(... and read in a similar fashion but I don't think the panel is meant to send any data. I have no idea what is in the box but I am sure it is the simplest of devices. Will it help if I cut open the box? Are there resources I can read to learn how to read and change the text displayed on a panel through serial connection.

EDIT : The panel has some kind of storage I suppose, since the text shows without computer connection and even after unplugging.

Answer 1

显示的文本可能是从微控制器的板载内存中读取的，您无法通过串行更改它，它由控制器运行的代码控制。