Multi-Station Dashboard and Station Discovery

One OpenHTF process is one station running one test. A production line has several. This page covers what OpenHTF ships for that — a multicast-based dashboard listing stations on the LAN — and what it leaves to you.

How a station announces itself

station_server.StationServer (the process behind the Operator UI) joins a multicast group and answers discovery queries with its host, port and station ID. Defaults come from openhtf.util.multicast:

Set them per station in a YAML file passed with --config-file — see Production deployment.

The dashboard server

python -m openhtf.output.servers.dashboard_server --dashboard-server-port 12000 --no-local-only

Opens http://localhost:12000: a list of every station discovered on the subnet, refreshed every --discovery-interval-s seconds (default 1), each linking to that station's own Operator UI. --no-local-only is required to list stations on other hosts; the default discovers only the local machine. All flags are on the CLI page.

The dashboard is a thin index. It does not aggregate results or history; clicking a station takes you to that station's UI, served by that station.

History per station

StationServer(history_path="/var/lib/openhtf/records") makes the station's UI list past runs from a directory of JSON records. Point OutputToJSON at the same directory:

RECORDS = "/var/lib/openhtf/records"

with station_server.StationServer(history_path=RECORDS) as server:
    web_launcher.launch("http://localhost:4444")
    while True:
        test = htf.Test(*phases)
        test.add_output_callbacks(
            json_factory.OutputToJSON(f"{RECORDS}/{{dut_id}}.{{start_time_millis}}.json", indent=2),
            server.publish_final_state,
        )
        test.execute(test_start=user_input.prompt_for_test_start())

History is per station and per directory; two stations do not share it.

Network considerations

• Multicast discovery needs the stations and the dashboard host on the same L2 segment (TTL 1) or a router configured for the group. Many factory VLANs block multicast; if the dashboard stays empty, that is the first thing to check.
• Station UIs bind all interfaces on station_server_port with no authentication. Restrict with a firewall or reverse proxy if the network is shared.
• --config-value station_id=EOL-03 on each launcher script keeps names unique when hostnames are generic.

Where the built-in tooling stops

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