Masterpiece: integration

Four subsystems are running, each on its own. Now comes the piece that turns them into a base: the central unit. It controls not a single device of the subsystems. It reads, sums up and raises alarms.

The overview#

Every subsystem gets a display on the central unit's panel: “Z_LS”, “Z_EN”, “Z_PR”, “Z_LG”, plus “Z_Basis” for the overall state. The colours are those from day 339 – green, yellow, red –, the number is the status. A missing status memory counts as a fault.

For that the central unit calls the same subroutine four times. It gets the name of the status memory, the name of the display and a bit number. The bit number is the system's place in the fault word.

Alarms#

Every system in fault sets its bit:

sge tmp s STOERUNG
ins faults tmp bit 1              # the system's bit in the fault word

The central unit finds new faults like the alarm centre on day 340: set now, not before. They keep the klaxon “Z_Alarm” on until the button “Z_Quittung” is pressed:

not tmp alt
and tmp faults tmp                # newly faulty: yes now, no before
move alt faults
or pending pending tmp

A warning (status 1) colours the panel yellow, but does not sound. A fault that has already been acknowledged only sounds again once it disappears and occurs anew.

What the central unit does not do#

It does not intervene. If power drops into stage 2, the central unit does not switch off any light – power did that itself long ago. The central unit reports it to the person. Tomorrow adds what it may request: orders to production. That too is a request over the interface, not a grab into someone else's device.