From the signals transmitted by the sensors, the analysers determine the number of passengers boarding and alighting. These figures are polled by an on-board computer for each door and stop and stored with reference to the individual stop. In order to allocate the counts to the individual doors, each vehicle door is assigned a door address in the respective analyser.
The analysers have one, two or four sensor connections and one or two door contact connections. This means that the sensors of a maximum of two doors can be connected to an analyser. Data transmission between the analyser and the sensor is controlled by a microcontroller. RS-232C levels are used on the connection cable to the sensor. The cable length between the sensor and the analyser is 15m as a maximum.
The analysers contain the following essential functional groups:
The power supply of the analysers is 24VDC (9.0VDC ... 32.0VDC). A LED at the front of the analysers indicates that the power supply is on.
The continuous recording of passenger figures requires an uninterruptible power supply to the analysers, also refer to section 6: Protecting Data Integrity. To allow easy connection of all cables (power supply, sensor, door contact, cable to the on-board computer) to the analysers, all cables are equipped with DIN plugs. Depending on the actual conditions, different analysers are installed – refer to Section 3.3 Selection of Analysers. The analysers are inserted in a support which secures quick and electrically insulated installation and which is available as an option. This support containing the analyser is shown in drawing_1a and in drawing_1b.