ACE IoT is pleased to announce the successful development of a powerful new integration between the Siemens Desigo API and the open-source Eclipse VOLTTRON technology. The new integration enables building owners and their vendors to acquire data from legacy Siemens controllers and transfer the data into a VOLTTRON-enabled Independent Data Layer (IDL) more easily than ever before. The integration has been thoroughly tested and ACE IoT and our customers are using the new VOLTTRON-Desigo integration to collect data from Siemens P2 controllers and readily ingest the data into 3rd party data management and analysis tools.

For entities tasked with designing and deploying advanced Energy Conservation Measures (ECMs) in buildings that have Siemens Desigo software running on top of legacy controllers, the new integration should be a game-changer. ACE IoT has released the DESIGO-VOLTTRON integration as an open-source project. Interested parties can download the code from ACE IoT’s GitHub repo.

Integration between VOLTTRON and Desigo facilitates both data acquisition and data analysis

ACE IoT anticipates that the new integration will be a particularly valuable tool for energy engineers and firms conducting retro-commissioning activities to improve the operational efficiency of buildings with Siemens legacy equipment. For entities experiencing technical challenges acquiring data from legacy Siemens equipment, the new code should help resolve a threshold obstacle to successful retro-commissioning projects. Using the new integration, firms can readily collect data from P2 controllers and spend retro-commissioning budgets analyzing data and designing ECMs rather than wrestling with data acquisition.

In addition to simplifying data collection from P2 controllers, the integration simplifies data analysis and data enrichment. The integration with Desigo is with the open-source VOLTTRON technology and, as a result, data acquired is easily enriched with data from sources other than the Desigo system, including data from distributed energy resources (DERs), IoT devices, and non-Siemens HVAC equipment. Also, because the data acquired from the legacy system streams into VOLTTRON, energy engineers and retro-commissioning firms are can readily apply their preferred software languages, data analysis tools and 3rd party applications to the collected data.

Built and tested via a powerful collaboration

To build and test the integration, ACE IoT had several key partners without whom developing and validating the integration would have been impossible. Our initial partner in the endeavor was Bernhard. Bernhard, a firm providing an energy-as-a-service offering to facilities owners and operators, was looking for a way to collect data more conveniently from customer buildings where DESIGO was running on top of legacy equipment. Bernhard’s Monitoring-based Commissioning (MBCx) team also sought an integration with the Desigo API that would allow Bernhard to deploy more effectively the ECMs that it deploys in facilities with newer HVAC systems. The team at Bernhard discussed this goal with ACE IoT and decided that the co-development of an open-source integration between the Desigo API and the open source VOLTTRON technology was an option worth exploring.

The facilities team at Ochsner Baptist Hospital, a large medical center in New Orleans, was also a key partner to the effort. Once ACE IoT developed an integration between VOLTTRON and the Desigo API, the next stage was testing the integration. Thanks to the support of the teams at Ochsner Baptist and Bernhard, ACE IoT implemented a series of tests in an in-situ deployment environment throughout Q3 and Q4 of 2023. As a result of the collaboration, the integration was able to be tested (safely) in a deployment environment that included real world conditions–this was a unique and important factor in the integration’s successful development.

The collaborative effort to develop an integration between VOLTTRON and the Desigo API also included Jim DeMatt, an Ecosystem Integration Engineer at Siemens’ API support team. Jim and Siemens’ API support team worked closely with Bernhard and ACE IoT during the development and testing of the integration. Indeed, Jim’s efforts and those of his colleagues demonstrated Siemens’ strong support for 3rd party integrations and illustrated Siemens’ commitment to a robust 3rd party ecosystem that can help Siemens customers realize the value of their HVAC equipment.

New pathway for integrating data from legacy systems now available for download

By December 2023, testing of the new integration was providing enhanced visibility into the performance of HVAC legacy systems at Ochsner Baptist and was enabling software-based optimizations of the legacy system. As of April 2024, Bernhard’s MBCx team is using the new integration to support its work at Ochsner Baptist. At ACE IoT, we hope that organizations considering using Tridium JACEs to acquire the data will explore whether an integration between Desigo and VOLTTRON might provide a better path forward.

Download the code for free at ACE IoT’s GitHub repo. If you would like to learn more about the open-source integration between VOLTTRON and the Siemens Desigo API, please contact Bill Maguire via

For more regular updates related to deployments of open, interoperable smart building technologies and related initiatives, follow ACE IoT on LinkedIN.