Project: alloy furnace

The furnace week ends with a chip that cooks steel without anyone having to stand next to it – and that makes everything safe at once when it gets too much.

The plant#

The rules#

• Temperature: below 950 K fuel on, from 1,100 K off. It ignites when fuel is coming and nothing is burning.
• Pressure: from 5,000 kPa exhaust on, below 4,000 kPa off again. While exhaust runs, no fuel.
• Mould: only open when RecipeHash reports steel. No iron, no slag. Mode is only the display on the furnace and stays out of it.
• Done message: if something lies in the output slot (slot 1), “Fertig” lights up.
• Emergency shutdown: above 40,000 kPa or with a missing furnace “Notaus” latches: fuel off, exhaust open, mould closed. Only when the pressure is below 4,000 kPa and someone presses “Quittieren” does it continue.

Latching and acknowledging#

The emergency shutdown is a fault with memory, as you know it from the state machines. It is set with or and cleared only under a double condition:

lbn tmp BUTTON HASH("Quittieren") Activate Average
slt tmp2 press P_SHUT
and tmp tmp tmp2
seqz tmp tmp
and estop estop tmp

If somebody presses too early, nothing happens. That is intended: a furnace at 35,000 kPa does not get safer by the press of a button.

Milestones#

1. Hold the temperature
2. Hold the pressure, fuel locked while venting
3. Mould only for steel
4. Done message
5. Emergency shutdown latches and can be acknowledged
6. Furnace missing: emergency shutdown