Success Story: Water

I. CUSTOMER ENVIRONMENT / PROJECT CONTEXT

Customer profile:

The Communauté urbaine de Montréal (the City of Montreal) treats 44% of all wastewater processed in Quebec treatment plants. Their Treatment Plant has one of the highest pumping capacities in North America. The wastewater treatment system network consists of a central treatment plant, and 68 hookup structures of which 36 are equipped with remotely controlled regulating structures. Hookup and regulating structures direct wastewater from trunk sewers through interceptors to the wastewater treatment plant. During rainy weather, sluice gates mounted in the regulating structure control the inflow of wastewater and rainwater in response to signals from the control centre at the Wastewater Treatment Plant and from the local PLC. The system also includes pumping stations and measuring points located throughout the system and supervised in real time.

Processes are controlled by SICOS, a third-party integrated control and supervision system. The system is connected to every one of the plant's processes and pieces of equipment via a 3.6 km fibre optic network. Over 12,000 I/O points are connected to SICOS.

Customer objective and constraints:

The existing regulating structure/gatehouse flap control system - using a third party protocol and communicating to the central DCS over Modbus - had to be upgraded to an Ethernet-based system with a single, standardized program for the 36 new gatehouse PACs.

Each of these PACs controls a different I/O configuration, depending on whether it is electric or hydraulic.

An additional 10 sites, pumping stations and measuring points, were also upgraded with the same control system.

II. SOLUTION IMPLEMENTATION

Implementation methodology (main phases):

Schneider Electric performed several on-site validation tests and provided solutions for adjusting the differently configured local I/O systems.

Solution overview (services, products, systems, architectures...):

At the heart of the new gatehouse flap control system are 36 identically programmed Premium PACs on a WAN network. They communicate over Ethernet Modbus TCP/IP to one of 5 Quantum data consolidation controllers. Local I/O adjustments are downloaded from the Quantum PAC to a site-specific address. Unity programming software facilitated mapping the I/O in the Quantum PACs, and allowed the creation of a standardized program for all the Premium PACs. The Quantum controllers communicate to the DCS via Modbus Plus.

Schneider Electric controllers use a standard, native protocol - Modbus Plus - to communicate with the SICOS system, thereby maximizing the amount of data that can be transferred.

Moreover, the Premium and Quantum PACs were programmed with Unity Pro software, which allowed the use of Unity's 5 IEC languages (IEC Ladder, Function Block Diagram, Sequential Function Chart, Structured Text and Instruction List).

III. RESULTS / ACHIEVEMENT

Customer benefits:

The new control system allows uninterrupted communication with the DCS while accessing the remote controllers with UnityPro for adjustments and troubleshooting. And the standard Internet browser allows remote monitoring with the Rack Viewer function.