Protocol Libraries

Our protocol libraries are written in safe Rust and compile to native code. Take advantage of their performance and safety from Rust, C/C++, Java, and .NET


Supports both client and server for Modbus TCP, Modbus RTU (serial), and the new secure Modbus specification (TLS).

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Supports both master and outstation over serial, TCP, UDP, and TLS. Fully automated level 2 conformance tests ensure interoperability with 3rd party systems.

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Publicly Available

Our libraries are openly developed with the full source code available for all to review. Secure software doesn't rely on obscurity and deserves scrutiny from researchers.

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Non-Commercial License

Anyone may use our libraries under the non-commercial license attached to the source code. This license allows non-production use cases such as evaluation, teaching, and training.

Commercial License

Tried our libraries and ready to put them in a product or service offering? Contact us to discuss the terms of a commercial license. We can craft an agreement to meet your needs.

What Others Are Saying

Don't just take it from us. Ask around. We've been working on software and security projects in electric power for over a decade.

"Adam is consistently leading the field on design and testing of industrial protocols and the latest development tool set innovations. Tech from Step Function I/O is a smart bet."

Bryan Owen, Security Architect, OSIsoft LLC

"Adam and the experts at Step Function I/O are more than just leaders in the industrial reliability and security space, they are renowned practitioners."

Ronnie Fabela, VP of Field Operations, Gravwell Inc

“At EPRI, we have built a number of protocol drivers and device simulators for DER applications that use the OpenDNP3 library. We are very impressed by the high-quality library and documentation.”

Jithendar Anandan, Smart Grid Developer, EPRI