Northeast Water Upgrades
Industry: Water & Waste Water
INTRODUCTIONA large municipality suffered from an aging DCS and communications infrastructure, causing frequent breakdowns. The client called on Optimation to upgrade its system, increase functionality and monitoring capabilities, and limit operator interaction.
SOLUTIONOptimation replaced the existing DCS system with Modicon Quantum PLCs with local, and in most cases, remote I/O (RIO). The PLCs were programmed using Modicon Concept IEC 61131-3 software, using ladder logic language. Because the system cannot be in a disabled state, most PLCs used redundant processors.
Optimation also provided additional functionality for the process pumps, allowing them to operate more efficiently and with less operator interaction, helping to prevent operator injury in case of an accident. Optimation moved new control logic out of the DCS and into the PLCs where it could be easily monitored and modified. The customer was unable to modify the existing DCS.
Optimation added alarming and trending screens to give personnel greater visibility into the process, monitored from most locations throughout the plant, and added local terminals and critical I/O points wherever failures could occur, in order to prevent costly equipment damage or operator injury in the event of an accident.
In cases where municipal buildings were far apart or noise was an issue, Optimation used protocol converters and fiber optic cable. In critical areas where redundant and failsafe I/O was required, Optimation used SIXNET I/O modules and local Red Lion indicators.
The user interface consists of Citect terminals, both touch and workstation, spread throughout the plant. Graphics consist of 2D representations of components and IEC flow diagrams of process flow. Optimation provided additional state table screens for technical personnel to reference and get a quick view of what was happening in the PLC. Local Magellis terminals were provided to control the process in case of failure to the main Citect system.
RESULTSAfter project completion:The client Maintenance Team is now able to troubleshoot the system resulting in less down time. Operators have additional time available to focus on the process rather than the operation. System monitoring is from one location resulting in faster response times to critical alarms and maintenance issues. Control code is processed more efficiently in the PLC where it belongs. Parts and service are readily available from many sources. As processes and equipment change, so can the new system.
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- Controls Engineering
- Electrical and Instrumentation Design
- Electrical and Instrumentation Engineering
- Software Engineering
PLC and DCS Systems
SCADA and HMI