Modbus TCP & RTU
Modbus TCP and Modbus RTU, native, no gateways
Modbus is the lingua franca of industrial communication. ScadaHud ships first-party drivers for Modbus TCP, Modbus RTU and Modbus ASCII so you can pull live values from PLCs, energy meters, VFDs, RTUs and gateways without a third-party OPC server in the middle.
What is Modbus?
Modbus is a serial and TCP/IP application protocol introduced by Modicon in 1979 and now the most widely deployed industrial protocol on the planet. The data model is simple: read or write coils, discrete inputs, input registers and holding registers, addressed by function code and slave ID. Modbus TCP carries the same PDU over a TCP socket on port 502; Modbus RTU runs over RS-485 / RS-232 with CRC-16. Most modern PLCs, energy meters, UPSes, and BMS controllers expose a Modbus interface either natively or via a gateway.
What ScadaHud's driver supports
- Modbus TCP, Modbus RTU over TCP and Modbus Serial (RTU and ASCII over RS-232 / RS-485)
- Function codes 1, 2, 3, 4 (read coils, discrete inputs, input registers, holding registers) and 5, 6, 15, 16 (writes)
- Auto-block optimization: contiguous tags are read in a single request to minimize wire traffic
- Per-slave-ID isolation on shared TCP connections, no transaction-ID race conditions
- Forced block reads for devices that require fixed register ranges (Socomec UPS, some Schneider gear)
- Per-tag byte-swap and word-swap configuration (AB, BA, ABCD, CDAB, BADC, DCBA)
- Int16, UInt16, Int32, UInt32, Int64, UInt64, Float32, Float64, Boolean and bit-packed types
- Configurable polling, deadband, retry and reconnect
- Human-readable Modbus exception messages (Illegal Function, Illegal Data Address, Slave Device Failure, etc.)
Common use cases
- Energy and power monitoring with Schneider PowerLogic, ABB M4M, Carlo Gavazzi, Janitza, Siemens SENTRON
- PLC tag acquisition from Modicon, Allen-Bradley (via gateway), Wago, Beckhoff, Phoenix Contact
- VFD monitoring (ABB, Danfoss, Schneider Altivar)
- Substation RTU and IED data on Modbus over serial or TCP
- BMS subsystems exposed via Modbus gateway
Schneider, Siemens, ABB, Modicon, Wago, Beckhoff, Phoenix Contact, Carlo Gavazzi, Janitza, Socomec, Eaton, Delta, Mitsubishi, Allen-Bradley (via gateway), Acrel, AE Solar, SMA, Huawei FusionSolar.
Book a live walkthrough.
Book a 30-minute live demo with one of our solution engineers. We will connect to a sample PLC and walk through tags, alarms, mimics, the digital twin, and historian queries.