- if data in the first variable indicates that a signal from a sensor was responded to, then:
- storing, in the second variable, data stored in the first variable;
- storing, in the first variable, data indicating that expiry of a timer was responded to; and
- entering a mode in which the processing apparatus is responsive to a signal from a sensor and responsive to expiry of a timer;
- if data in the first variable indicates that expiry of a timer was responded to, then:
- storing, in the second variable, data stored in the first variable;
- storing, in the first variable, a data indicating that expiry of a timer was responded to;
- transmitting data indicating an absence; and
- entering a mode in which the processing apparatus is responsive to a signal from a sensor.
In a fifth aspect, this specification describes an apparatus configured to perform the method described above with reference to the fourth aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more fully understood, embodiments thereof will now be described by way of example only, with reference to the accompanying figures, in which: