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The latest entry into our Digitalization Digest consists of a project for a Pennsylvania Borough of an existing Grit Well control system that was based on a DCS system. The system was proving to be very costly and now effectively obsolete and could not be readily expanded. The system’s age made replacement of parts difficult, with long lead times and limited sources for the required parts.

For the new system, it was decided that the remote DCS I/O would best be a new Modicon hardware, to include a new PLC and panel to replace the existing remote panel. Modicon provided compatibility with the WWTP – supplier Activar VFDs as well as accessibility for product spares and replacements. The software selected for the control system was Ignition, an affordable product providing unlimited clients, unlimited data points, unlimited screens and remote alarming via email/SMS. A further advantage to the Ignition platform is that scalability is very cost-effective relative to the leading competitors. Additionally, the Ignition software was selected by PDA for the SCADA aspect as well as for the overall visualization of the project.

The new system is a standalone control system operated via Ignition. For estimation purposes, data collection was assumed to occur on up to 25 points and initially, the data points were collected and stored within the existing SQL database for the DCS system. As the changeover progressed the existing database became the Ignition database and provided historical long-term storage for both data sets.  This action was predicated upon PDA having full access to the SQL database.

PDA provided the labor for engineering and data services, as well as for the system I/O requirements.  PDA also provided hardware, including the main control panel that housed the controller, all M340 rack-based I/Os and an M340 rack for future expansion. This panel was also fitted with a door-mounted HMI touch screen for local control of the system. All control equipment was pre-installed in the cabinet, together with E-stop equipment, power requirements, and miscellaneous panel components.

At the completion of the project an internal assessment led to the following observations:

• Any potential customer can benefit from the solution that was presented to the Pennsylvania Borough. It is applicable to a large municipal system or a large manufacturing plant, looking for a more custom based solution.
• The focus of the solution was to alleviate ever-rising costs in maintaining older control systems and yet avoid licensing costs that can force a client to stay with the obsolete system.
• The water authority had the ability to test the system and, if satisfied, begin their phased migration.
• Ignition creates an interface that is user-friendly and both flexible and expandable. The best practices used by PDA ensure that the platform is pre-loaded with useful scripts and memory tags, allowing convenient setting up of new screens and advanced techniques, as well as maintaining low costs for any future modifications.
• The most difficult part of the project was determining what could be removed from the existing DCS system and incorporated into the new controlled system.
• Training was provided allowing the customer to become self-sufficient.

PDA is a full-service, CSIA Certified industrial control systems integration firm. Our Controls Engineering group specializes in physical automation system design, programming, and commissioning. We also feature a dedicated Digitalization Group (DSG) that connects automated equipment and systems to the business system environment including protected recipe systems, data collection and reporting, and data historian implementation. DSG can provide the systems you need to set your systems up for proper operation and then provide the tools you need to make sure you execute as planned.

Our Digitalization Digest includes articles and thoughts regarding manufacturing plant digitalization.

Posted In: Digitalization Digest