It says "technical" on instruction manual. only 1-4 zones are used.
Technical (TC) (Key in 08). Use this zone type when you want to monitor equipment, for example a freezer, without raising a full alarm. If a technical alarm zone is activated while the system is set, the system makes no audible alarm. However, when a user unsets the system the keypad indicates a fault.If a technical alarm zone is activated while the system is unset then the system starts a pulsed tone from the keypad. If programmed, the control unit also starts communication. When a user enters a valid code the keypad stops the tone and displays the zone.