Schiphol Airport, one of the largest and most important gateways of Europe, is controlled by an immense system of automated functions. The condition of all these elevators, automatic doors, moving staircases, barriers, power supplies, emergency buttons, etcetera, is monitored by a central system, receiving nearly 25.000 signals from the vast amount of equipment on Schiphol’s enormous area. After two decades of service, the control system needs an intensive update.

The Challenge

Schiphol Airport is expanding rapidly and so is the number of devices to be monitored by the CSS, which stands for - in Dutch - Centraal Signaleringsysteem Schiphol. In order to maintain the power to control all the connected equipment, it is necessary to increase the number of incoming signals that need to be checked simultaneously.

The present control system is an AEG Modicon PLC (A-U130). The possibilities of the system need extension, to allow more and different functions.

But the age of the PLC prevents the delivery of spare parts; the necessary hardware to expand is therefore not, or hardly available. Conclusion: adapting the present system to the new demands is not a preferable option.

The Solution

Mulder-Hardenberg has successfully delivered and implemented Opto 22 systems for the CSS in the past. Therefore, the company was invited to come up with a solution to replace the present control system.

After careful evaluation and several tests, Mulder-Hardenberg developed a number of custom designed products based on Opto 22 SNAP PAC (Programmable Automation Controller) Ethernet hardware. Modular Linux software was suggested and implemented to connect all the equipment to the database. To avoid malfunctioning and loss of time M-H decides to leave the connected equipment and the cables totally intact. For the same reason, the implementation of a new control system and renewal of necessary parts and devices should take as little time as possible.

Monitoring is a vital aspect on Schiphol Airport, a city that never sleeps. It is therefore very important that the time the system is ‘off air’, remains as short as possible.

The Implementation

In order to keep the ‘off air’ time as short as possible, the chassis of the new control system was built with exactly the same dimensions as the old version. Therefore, the system could be removed from the entire cable household plus connectors - and the new version reconnected - without altering any part of the other equipment.

It took a maximum of three hours per location - with a total amount of 53 - to replace the entire control system. In advance, we expected to be 8 hours ‘off air’ for each location.

The result

The new control system works very well. Based on previous experiences, Mulder-Hardenberg assures Schiphol Airport they can totally rely on M-H’s custom made products based on Opto 22. The capacity of the new system is fully adequate. Future expansions will be executed with the same Opto 22 PAC hardware. The ICT/CSS department of the Schiphol group is considering Mulder-Hardenberg for this application, as well as others.