Recent changes to legislation make it a requirement that all passengers in coaches and minibuses must use seatbelts to reduce the chance of injury in the event of an accident. To comply with this legislation, a system integrator approached Amplicon for a reliable and flexible I/O system that would provide the driver with real-time information about passengers’ use of seat belts. Further options for the system included the addition of security cameras and a CAN (Controller Area Network) link to the engine management system.
We were given an initial specification to monitor a number of different passenger vehicles. These ranged from minibuses up to double-decker coaches. The system was required to monitor seat pressure switches and seat belt sensors with a varying number of seats in to a common system. This information would then be shown on a compact display for the driver to determine if any occupied seats have unbuckled seat belts and raise an alert. The whole system had to be easy to operate, scaleable and be highly reliable.
A flexible and reliable system was needed so it was decided to use the ADAM 5550KW Programmable Automation Controller (PAC). PAC’s are designed for multipurpose tasks that require the performance of an industrial computer with the reliability of a PLC. The ADAM 5550KW is an eight slot controller which allows you to choose a variety of I/O modules to suit your particular application. The ADAM-5051S module was chosen for this application because it has 16 isolated digital inputs.
Two channels were required per seat, which meant that each controller could monitor vehicles with up to 64 indivudual seats. Larger vehicles could also be monitored by using an expansion unit for additional modules, connecting to the controller on its RS485 serial communication bus.
The ADAM 5550KW features five standard IEC61131 3 programming languages so both PLC and PC users can develop monitoring and control applications with their own choice of programming language.
• Ladder Logic
• Function Block Diagram
• Sequential Function Chart
• Structure Text
• Instruction List
The KW MultiProg software runs on the ProConOS real-time operating system. This easy to use software even allows the integrator to use different programming languages in the same application to suit particular I/O requirements.
For the driver’s display. the TPC-660G 6.4” touch panel computer was chosen. The choice of CompactFlash or a durable 2.5” laptop style hard disk drive meant that there was plenty of room for expansion of applications.
On the TPC-660G touch panel computer, DAQFactory SCADA software was installed to provide an easy to interpret graphical interface for the driver to quickly identify occupied seats where the seat belt is not fastened, thus allowing compliance with the requirements of the legislation.
The system was easy to install with screw terminals and RJ45 connectors on these light-weight and compact panel mounted units with a DIN Rail option where appropriate.
Due to the flexibility of using Ethernet and the modular design for distributed I/O applications, the system has the potential to be expanded to an almost limitless amount of sensor inputs making it suitable for the largest vehicles. There is also the ability to add other modules and Ethernet devices such as IP cameras to provide an onboard security features. The system can also be extended to other vehicle CAN bus systems allowing compatibility with a wide range of engines and other vehicle systems giving drivers the full picture.
Amplicon was the supplier of choice as we were able to offer 40 years experience with industrial electronic systems encompassing data acquisition, industrial networking and computing solutions. By talking to one of our applications engineers, the right equipment was selected on time and within budget.