Modbus RTU
A Master/Slave, half-duplex polling architecture over differential signalling. The Master polls individual node addresses sequentially to read or write binary coils and 16-bit registers from field devices, using CRC-16 error checking.
Type
Serial Bus (EIA-485)
Typical Latency
10ms–100ms (depends on baud rate and polling-chain length).
Hardware Requirements
RS485/RS232 link, twisted-pair shielded cable (120Ω termination at bus ends), serial-to-USB/IP converters, or a dedicated edge gateway serial port.
Security
None natively — relies on physical network isolation or a secure serial-to-Ethernet bridge.
Typical Use Case
Battery monitoring arrays, energy meters, multi-drop temperature sensors and legacy field instruments.
Connection Parameters
- Default port
- COM1 / ttyUSB0
- Baud rates
- 9600, 19200, 38400, 115200
- Data bits
- 8
- Parity / stop
- None (1 stop) or Even (1 stop)
Need Modbus RTU integration for your plant?
Our engineers configure drivers, gateways and security for this protocol as part of every Factomation deployment.