What this simulator helps test
SPX works as a Modbus TCP simulator for register maps, reads, writes, scaling, timing behavior, and fault conditions. The simulator is tied to a running digital twin, so register values can represent system behavior instead of static placeholders.
Why SPX
SPX lets software teams test Modbus integrations against controllable behavior before hardware is available. Teams can inspect live state, reproduce edge cases, and later turn the same simulator workflow into repeatable QA or CI checks.