Modbus TCP has been around since 1979. It is still everywhere. PLCs, VFDs, power meters, temperature controllers.
The CollatrEdge Modbus plugin reads coils, discrete inputs, input registers, and holding registers. It handles four byte orders (ABCD, CDAB, BADC, DCBA) because different manufacturers made different choices and none of them documented why. It does scaling and offset. It does bit extraction from 16-bit registers. It batches reads with configurable gap limits to minimise round trips.
It is read-only. Permanently. Writing to a Modbus device from a data collection agent is a safety risk we are not willing to take. That decision is in the PRD and it is not negotiable.
The OPC-UA plugin handles subscriptions, browsing, and certificate trust. Trust-on-first-use with explicit pinning, because asking a maintenance engineer to manage a PKI infrastructure is not a serious suggestion.
The MQTT consumer reads from brokers in multiple data formats with automatic detection.
Three protocols. Three ways into the factory. That covers most of what is out there.