Project Introduction:
This expressway tunnel monitoring system utilizes a distributed Ethernet-based networking control architecture and includes central monitoring system, zone controllers and field site controllers. The ultra-compact and high cost-performance controller greatly simplifies system architecture and connection.

System Requirements: Tunnels can be classified into four categories by length: short tunnels (<250m), middle long tunnels (250m ~ 1000m), long tunnels (1000m ~ 3000m) and super long tunnels (>3000m). The longer the tunnel, the more monitoring devices are needed.

According to the sub-systems, the tunnel monitoring system can be divided into: thelightingsystem, a ventilating system, traffic guidance system, CCTV system, fire alarm system, fire-fighting control system, emergency telephone system, broadcasting system, and additional tertiary tasks. The tunnel monitoring system can be classified into four groups by device: measuring devices, controlling devices, display devices and communication devices. Measuring devices include fire-alarm probes, vehicle detectors, COVI, visibility sensors, and wind sensors. The controlling devices include a traffic area controller, illuminated area controller, and ventilated area. Display devices include a computer workstation, large-scale monitor, and solar alarm. Finally the communication devices include switches, hubs, serial devices communication equipment, optical transmitter and receiver.

System Diagram:

System Description:
The zone controllers (PAC) are used to collect information of field measuring devices, process the information and send the information to the local control center. Control commands from the local control center are then sent to the zone controllers in order to directly control the corresponding devices. If the connection between the local control center and zone controllers is broken, then zone controllers can independently control field devices. Therefore, the zone controllers must be efficient and highly reliable.

AdvantechPAC is used as tunnel monitoring zone controller. CPU supports industrial Ethernet bus and various Fieldbus, so it’s cost-effective and convenient to use. The control mode uses remote intelligent distributed architecture with CPU, featuring system openness and high compatibility; its complex I/O and high-performance function module could meet signal processing commands of monitoring system. Every module is linked by side connection mode; it provides multiple functionality and program capacity, and is easy to detach and maintain.

Conclusion:
APAX-5520KW CPU can be simply used as the I/O control processor. In this way, it will not be disturbed by any other task and will thus achieve the most efficient and real-time control capability. APAX-5520KW is provided with standard IEC-61131-3 development tools. Multiprog KW software and stable ProConOS enables engineers to develop programs and applications rapidly.