Case Studies

Modular PLC Code for Maritime Installations

Posted in HMI and SCADA, Manufacturing Automation and Intelligence, PLC Programming, Siemens PLC


DMC developed a modular plc program used to control a ballast water treatment system for large ships. This solution was adaptable to highly varied ship layouts and PLC configurations with minimal time required to install specific software modifications. 


When a ship has unloaded cargo at one port, to stay balanced, the ship must pump water into holding tanks called ballast tanks. Per IMO D2 Standards, before a ship can release the ballast water at the next port, the water must be treated to remove any organisms, therefore, preventing contamination of the port's natural eco-system by invasive species.

DMC’s customer works with a variety of ships all over the world, which can each have unique ballast tanks. DMC was brought on to create flexible PLC and HMI code that can be deployed to a variety of vessels with minimal ship specific configuration.

We first wrote a software specification for the client detailing the program operation. This specification laid out a high-level architecture that would allow a single HMI and PLC program to be deployed to any ship, no matter the ballast tank configuration. It included HMI wireframes and descriptions of PLC sequences. After it was approved, DMC began the development of PLC code based on this spec. As part of this development, DMC created custom simulation logic and ran extensive simulation testing during off-line development. This was essential to ensure a successful first deployment, as full system hardware testing was not possible until the first production installs on a ship.

Each ship had unique PLC hardware, ballast tank configuration, and operational parameters. As developed, the modular PLC code allowed it to be deployed to different sites with minimal configuration time. As the project progressed, we implemented user experience improvements and new features. Because of the flexible code base, these changes were easy to implement and track, allowing remote updates to ships where commissioning was complete.

DMC engineers traveled internationally on extremely short notice to ensure installation and commissioning success. This included living on and traveling with ships to ensure the correct operation of the system. DMC also provided remote support at various hours of the day and night because the projects were deployed all over the world.

With another commissioning beginning soon and more scheduled for the future, these engineers have earned themselves a new nickname: the DMSea team.

Learn more about DMC's PLC Programming services and Siemens expertise.

Customer Benefits

  • Flexible code able to be deployed to vessels with many variations
  • User-friendly HMI
  • International and overnight support
  • Detailed issue tracking and resolution
  • Comprehensive simulation testing before the first install