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infra:led-display-sign

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

Resources

/srv/hackeriet-wiki/dokuwiki/data/pages/infra/led-display-sign.txt · Last modified: by atluxity