Modbus RTU
The serial workhorse of industrial automation
Modbus RTU is the de-facto serial protocol for connecting energy meters, PLCs, drives, transmitters and I/O devices over RS-485. Every Wiman gateway acts as a Modbus RTU master, polling field devices on a long-haul RS-485 bus and surfacing their registers as clean tag data.
Where it is used
- Energy meters, multi-function meters and sub-meters
- Variable-frequency drives and motor controllers
- Transmitters: temperature, pressure, flow, level
- PLCs and process I/O on the plant floor
How Wiman supports it
Master · Up to 32 slaves per bus (extendable)
- Function codes 01, 02, 03, 04, 05, 06, 15, 16 — read & write, coils & holding
- Per-slave polling intervals and grouped register reads for efficiency
- Configurable baud (1200 – 115200), parity, stop bits
- CRC validation, retry & timeout handling out of the box
- Mapped to clean tags and forwarded over MQTT / HTTP upstream
Integration tip
Daisy-chain devices on a single twisted pair, keep stubs short, terminate at both ends of the bus.
Wiman gateways and converters that speak Modbus RTU
Every model below ships with Modbus RTU support today. Pick by connectivity and tag count — they all speak the same upstream protocol family.
MAX 4G + LAN Gateway
Dual-network flagship gateway with 4G LTE and wired Ethernet.
MAX 4G + WiFi Gateway
Flagship capacity with 4G LTE and wireless LAN backhaul.
PRO 4G Gateway
Secure cellular gateway with SSL, dual servers and battery backup.
PRO Ethernet Gateway
Wired PRO gateway with secure dual-server publishing.
PRO WiFi Gateway
Wireless PRO gateway with SSL and dual-server publishing.
LITE 4G Gateway
Cost-effective 4G gateway for everyday remote monitoring.
LITE Ethernet Gateway
Wired LITE gateway for stable in-plant monitoring.
LITE WiFi Gateway
Wireless LITE gateway for fast, cable-free rollout.
WT30i Analog Input Card
Compact analog Modbus I/O for reliable voltage-input monitoring.
WT36i Analog/Digital + Relay Card
Versatile Modbus I/O with analog, digital inputs and relay output.
WT60i High-Capacity I/O Card
High-capacity analog/digital Modbus expansion for complex systems.
WE62C Modbus RTU ↔ TCP Converter
Industrial RS485 Modbus RTU to Modbus TCP/IP converter.
Building with Modbus RTU?
Send us your device list, protocol mix and target platform — our engineers will recommend the right gateway or converter, and email you a datasheet.