Stopping on purpose: hcf

A pump fills the methane tank in the storage area. If the pressure rises above the limit, it has to stop – immediately and for good. The obvious idea: the chip simply halts. There is even an instruction of its own for that.

hcf: halt and catch fire#

hcf has no operands. The name is an old computing joke. In Stationeers it is meant literally:

• The chip reports error 16 (ChipCatchingFire) and executes no further instruction.
• The chip itself burns.
• The housing creates a spark in the surrounding air and a small explosion right where it sits.

bgt press MAXPRESS emergency   # limit exceeded?
j start
emergency:
hcf                            # error 16, chip burns

What happens after the halt#

The crucial part is written nowhere in the code: a halted chip switches nothing off. Every device keeps the value it received last. If the pump was running at the hcf, it keeps running – into the tank that is already too full.

The same goes for the quieter ways of stopping a chip:

A halt loop looks like this:

halt:
yield
j halt       # chip is alive but does nothing any more

Better: the lock state#

A lock state keeps the chip alive. It remembers the fault in a register, sets all devices safe every tick and only releases them once someone acknowledges and the cause is gone:

sgt tmp press MAXPRESS
select lock tmp OVERPRESS lock   # remember the fault
sle tmp press MAXPRESS           # cause gone?
and tmp tmp button               # ... and acknowledged?
select lock tmp 0 lock           # then release
seqz tmp lock
and pump pump tmp                # locked: pump off

That way the pump stays off, the display names the cause, and the chip keeps watching – even if the sensor disappears in between.