Table of Contents
Ericsson / Alpha-American 4200C LED Sign
This page documents the large LED sign acquired by Hackeriet, gifted by pere and asle.
Overview
This is an Ericsson-branded, Alpha-American / Adaptive Micro Systems 4200C LED sign.
It is a programmable LED display commonly used for transit, public information, or industrial messaging systems.
- Model: 4200C
- Manufacture Date: 2004-04-08
- Power: 100–240V AC, 50/60Hz, 1.5A
- Status: Fully operational, displaying test message on boot. Unknown operational method.
- For indoor use only.
Ports
The sign has a RJ-style modular port on the back panel with:
- RS-232 IN
- RS-485 IN
- RS-485 OUT
It also has an IR sensor hidden behind a red sticker, visible when removing a panel.
Dongle
A small dongle with resistors was included, likely serving as a RS-485 termination and bias dongle.
Communication
The sign probably uses the Alpha Sign Communications Protocol, which is:
- A structured serial protocol using STX/ETX framed packets.
- Allows sending:
- Text messages
- Control commands (clear, brightness, modes)
- Time-based messages
Serial Configuration
Suggestion for initial connection (untested):
- Interface: RS-232 IN (single device)
- Baud rate: 9600 or 19200
- Data bits: 8
- Parity: None
- Stop bits: 1
- Flow control: None