The fire-alarm panel reports a fault condition — either a supervisory signal (a closed or tampered valve, low water / air pressure, low tank level: the suppression side may not perform) or a trouble signal (a device or loop fault, ground fault, loss of AC power, a failing panel battery: the detection side may not perform). Both mean the system may not do its job in a fire, so both are surfaced and referred to the licensed provider. The supervisory / trouble distinction is kept internal; to the customer it reads as one panel fault signal.
fire_system_readinesspanel_supervisory = 1 OR panel_trouble = 1 (raises panel fault signal)