CP3 version 3003
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MZC
Typically, one MZC comprises a level of the parking facility, but it can also be a part of a level or even the
entire carpark. An MZC has a certain amount of parking spaces available, and the function of the MZC
system is to detect and count the cars entering and leaving the MZC and thus keep track of the number of
available spaces.
The counting system transmits the availability number for each MZC and allows the MZC to be read by local
or totalizing displays. This communication takes place in the SBP2CPY24 part, where the carpark software is
located.
Detection Points (DPOs)
A detection point is a lane or driveway where cars enter or leave an MZC. A typical example of a DPO is a
ramp between two floors, but it could also be the entry point from the street into the Carpark, or the exit
point. In many cases one and the same DPO is involved in two MZCs. For example, a DPO which is an exit
point for floor 2 can, at the same time, be an entry point for floor 3. The MZC system can handle maximum
40 DPOs. Each DPO consists of minimum one sensor (‘One-sensor DPO’), but normally of two sensors
(‘Two-sensor DPO’).
Each detection point needs sensors connected to the 3-wire Dupline® bus to detect passing cars. Dupline®
ultrasonic sensors are usually used, but other sensor types, like standard photoelectric sensors or loop
detectors, can be employed. Connection is made by coupling the sensor output to a Dupline® input
module.
The MZC provides the option to use either one or two sensors in each DPO. We recommend two sensors
with a distance of 2
m between them because this solution offers the possibility to detect the direction of
the car and allows a more efficient filtering to avoid false detections. Please refer to the section ‘Mounting
the Sensors’ for further information. Sometimes cars go in the wrong direction in a unidirectional lane, and
in a two-sensor solution, the MZC is able to manage this problem so that the count will still be correct. In
bidirectional lanes two sensors are mandatory.
When configuring detection points, it is possible to define a timeout value. This timeout feature is only to
be used in case of a long distance (more than 3 m) between sensor 1 and sensor 2. The timeout allows
accurate car detection as long as the delay period is shorter than the timeout value from the moment
where sensor 1 becomes inactive till the moment where sensor 2 becomes active. For a typical distance of
2
m between the sensors, 1 sec. is the recommended value. Too high a value increases the risk of detection
faults.
Single-sensor DPOs are mainly implemented when it is impossible or difficult to use two sensors, for
example in an outdoor installation with loop detectors.