Digital andon boards replace physical three-color light stacks with screens that display the line status the plant andon or MES system already publishes. CastHub shows it as a web page slide pointing at the status page that system publishes with no login, or as an image slide refreshed on a schedule, with green-yellow-red status, elapsed alert time, station ID, and shift-level alert history. No direct PLC, OPC-UA or Modbus connection is documented. The logged data feeds kaizen reviews and root-cause analysis, which physical light stacks cannot support.

A lean manufacturing or operations team can use line-side and supervisor-area screens to display the real-time andon status the line system publishes, with elapsed alert time, station ID, alert history, and root-cause categories visible at a glance, replacing the legacy three-color light stack and creating queryable data for continuous improvement reviews.

What is an andon system?

Andon originates from the Toyota Production System. The word means “paper lantern” in Japanese; the original implementation used physical light stacks to signal production line status. The system supports jidoka (autonomation): any worker can stop the line when a defect or issue is detected. Traditional three-color stacks signal status (green=running, yellow=warning, red=stopped) but record nothing. Digital andon adds data logging, historical context, and integration with manufacturing digital signage infrastructure.

How does a digital andon board work?

The plant andon or MES system already computes line status. CastHub displays that status by pointing a web page slide at a public status URL with no login, or by showing an image slide the plant exports on a schedule, so the affected station, alert type and elapsed alert time appear as the source publishes them and resolved alerts move to the history pane. PLC traffic stays on the production network. Web page slides play on Android TV, the Amazon Signage Stick and Apple TV, not on Tizen or Roku, and they never cache offline.

What does a digital andon board display look like?

Top: line status indicator (green/yellow/red), affected station number, elapsed alert time, alert type code. Middle: alert history for the current shift with resolution times. Bottom: shift-level summary stats including alerts triggered, average resolution time, and Mean Time To Repair (MTTR) trend. The layout reads at 10 to 20 feet for line-side viewing and consolidates shift handover data for the supervisor view.

Which PLCs work with digital andon?

CastHub connects to no PLC. Allen-Bradley (Rockwell ControlLogix and CompactLogix), Siemens (S7-1200, S7-1500), Mitsubishi (FX, Q, iQ-R) and Schneider Electric (Modicon) expose data over OPC-UA, Modbus, EtherNet/IP or Profinet to the historian, SCADA or MES the plant runs, which stays on the production network. Whatever that system publishes as a web page or an exported image is what CastHub puts on the screen.

PLC manufacturer	Common product lines	Protocol to the plant system	How CastHub displays it
Allen-Bradley (Rockwell)	ControlLogix, CompactLogix	OPC-UA, EtherNet/IP	Web page or image slide of the published status
Siemens	S7-1200, S7-1500	OPC-UA, Profinet	Web page or image slide of the published status
Mitsubishi	FX, Q, iQ-R	MELSEC, OPC-UA	Web page or image slide of the published status
Schneider Electric	Modicon	Modbus, OPC-UA	Web page or image slide of the published status

How does andon data feed continuous improvement?

Logged alert data reveals patterns invisible in real-time observation: which stations trigger most often, which alert types take longest to resolve, which shifts have higher alert rates, and which root-cause categories dominate. The data feeds kaizen events, 5-Whys root-cause analysis, and OEE optimization. Pair andon history with OEE production board data to correlate alerts with downtime impact and prioritize the highest-ROI improvements.

What hardware does a digital andon board use?

Industrial-grade 43″ to 55″ displays at 500 to 1,500 nits brightness, mounted 6 to 10 feet above floor level for line-side visibility. Anti-vibration mounts are required near heavy machinery. Industrial media players at $400 to $800 handle harsh environments where temperature, dust, or vibration exceed consumer tolerances. The Amazon Signage Stick, $99.99 on Amazon, works in cleaner office-adjacent areas like supervisor stations or breakrooms. Combine andon hardware with safety signage hardware on the same network.