Steel mini-mill

An electric arc furnace melt shop and a continuous caster in one material flow, over OPC UA. Eight devices and 122 tags.

This is the only solution here that is both at once, and the coupling is the demonstration.

The furnace melts a heat as an ISA-88 batch. The caster runs a strand continuously. A ladle furnace joins them. The caster is the pacemaker, and the melt shop is sized to run about a minute ahead of it, so a delay upstream propagates rather than being absorbed.

Nothing in the cost chain is a rule that says if fault then cost. The numbers come out of the process model.

The mill also demonstrates republishing northbound. With the Edge's own OPC UA server enabled, the full chain runs simulator, to Edge OPC UA client driver, to DeviceHub, to Edge OPC UA server, to an MES client browsing the address space.

That is the only place in this set where Litmus Edge is shown as an aggregator rather than as a collector.

Eight DeviceHub devices covering the furnace, ladle furnace, caster, tundish, mould, scrap yard and utilities, with 122 tags over OPC UA. A Digital Twin model and instance per unit. Analytics groups behind the specific energy, demand charge, cast rate and grade compliance figures.

The solution ships two ways. Use the registry if the host can reach Google Artifact Registry, and the downloaded archive if it cannot.

Requires a read-only registry credential, supplied by Litmus separately.

Save this as docker-compose.yml:

Or, without Docker Compose, run the same image with the same .env:

Flags given with -e take precedence over .env, so change APPLY_ON_START or EDGE_VERIFY_TLS on the command line rather than in the file.

Open http://localhost:4017.

The page stays on its waiting panel until the Edge carries this solution's devices. That is deliberate: the simulation does not tick and no value is shown until Litmus Edge is verified to hold the devices and poll them, so nothing on screen can be mistaken for data that never made the trip. With APPLY_ON_START at its default of 1 the solution configures the Edge itself on startup, which takes 30 to 60 seconds. If you set it to 0, or the apply failed, press Apply to Edge in the page header.

Download steel-minimill-demo-0.6.1-amd64.tar.gz from the solution's page on portal.litmus.io. The archive is the container image, not a source bundle, and needs no registry access.

docker load prints the image it added:

That reference is the one the compose file above already names, so the same docker-compose.yml and .env, or the docker run command above, now work offline with no docker login:

To run it without Compose, pass the same three values on the command line:

Set SPEED to 1 to demonstrate breakout detection on the Edge. The row 1 to row 2 thermal lag is about six seconds, and a speed multiplier divides the polls across it.

This solution can also publish its 8 Digital Twins into Litmus Unify, one message per asset under litmus-demo/minimill-01/.... It stays off until two things are true: the UNIFY_ values above are set, and the Litmus Edge has a Litmus UNS connector, which the Solutions provisioner can pair in one click. The next apply then publishes the twins, the page header shows how many are arriving, and removing the solution from the Edge removes its branch from Unify as well. Leave the values empty to keep Unify out of it.

Across the top: the heat in progress and its phase, specific energy, the billed demand peak and what it costs, tap to tap time, mill demand now, furnace share of it, cast rate and grade compliance.

Below, the mill itself: the furnace with its electrodes regulating and the scrap pile melting into the bath, the ladle furnace, and the tundish feeding the mould with the strand withdrawing at cast speed.

Faults include slag foam collapse, a tundish level excursion, a mould friction rise towards a breakout, and a scrap charge carrying high copper.

Use Clean up in the Solutions provisioner to remove what it created on the Edge.

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