For the following question we expect your answer to cover three to five pages (drawings included) If you want to do more, its your call - one page will not be accepted.

If you did not get the answers from the webinar or cannot find it in the notes, please e-mail your lecturer so he can give you a nudge in the right direction.

A water utility in a city has its control center located in a house in the suburbs. The water main, running in a circular fashion around the city, has four pumping/filtration stations (A, B, C and D), spaced approximately 12 km apart.

Assume single mode fiber is available between all the pumping stations and wherever else you may need it.

It has been decided that, as a matter of policy, Ethernet will be used throughout for data communications, with a star topology within the control center (interconnecting servers, HMIs, etc.) and a ring topology for linking the pumping stations to the control center.

The RTUs are to be connected to each other, and to the central network, with an HSR ring as per IEC 62439-3 (not just any redundant ring technology). Please note: a ring topology and not a star/ring.

A fifth station, E, monitors the water level in a dam, situated on top of a mountain overlooking the city. There is no cabling available in this case and point-to-point (terrestrial) wireless, with or without repeaters, has been ruled out for various reasons.

At the control center there are three HMI stations and a historian, apart from the SCADA server. The historian resides in a DMZ.

At each pumping station there is an RTU with analog inputs, analog outputs, digital inputs, and digital outputs. Do not worry too much about the numbers here, lets assume that a few of each will do.

The SCADA network needs to be connected to the corporate network.

Keep security issues in mind. All connections leading out of the control centre must be firewalled.

Draw a DETAILED diagram of your system, showing all components and interconnections. Please do not draw diagrams by hand. Snag your drawings in JPG format, then paste them into this document. Please draw star configurations as stars, and rings as rings. Include your name or initials somewhere to identify the drawing as your own. (10 marks)

Provide a description of your system, pointing out any assumptions you have made. About 1 page will be sufficient. Please make it a structured description with the following headings (properly numbered). (5 marks)

Ethernet infrastructure

Wireless infrastructure

Redundancy

Security

Connection to the corporate network

Give full details of the following devices. Include brand name, model number and picture (snag) of the particular device you are using. The information must be sufficient to find the datasheets on the Internet. (6 marks)

Central switch

Ring switches

Wireless modems

Give full details of the RTUs. Include brand name, model number, I/O configuration and snag of the particular device you are using. (4 marks)

Note: This question is mandatory. All 4 sections must be answered and students must obtain at least 20/25 in order to be deemed competent.