What is Modbus?
Modbus serial/TCP protocol
Modbus is a simple, open, register-based communication protocol widely used to connect industrial and building devices — PLCs, meters, drives, and sensors — over serial (RTU) or Ethernet (TCP/IP).
How Modbus works
Modbus uses a client/server (formerly master/slave) model: a client reads and writes registers and coils on server devices. Its simplicity and ubiquity make it the lingua franca for energy meters, variable-speed drives, and instrumentation.
Modbus RTU vs. Modbus TCP
Modbus RTU is a compact binary protocol over RS-485 serial; Modbus TCP carries the same data model over Ethernet. Gateways routinely bridge Modbus devices into BACnet-based BMS or SCADA platforms.
Frequently asked questions
Is Modbus still used today?+
Yes — it remains one of the most widely deployed industrial protocols because it is simple, open, and supported by virtually every meter, drive, and controller.
Can Modbus and BACnet work together?+
Yes. Protocol gateways map Modbus registers to BACnet objects so meters and plant on Modbus appear natively in a BACnet BMS.
Pontis Systems Engineering
Controls & Critical Infrastructure Engineering Team
The Pontis Systems engineering team designs, integrates, and commissions BMS, SCADA, data-center, and industrial-automation systems across Africa. As a Schneider Electric EcoXpert™ certified partner and Digital Realty delivery partner, the team works to global standards on mission-critical infrastructure.
Related terms
Need Industrial Automation engineering in Africa?
Pontis Systems designs, integrates, and commissions to global standards.
Request a consultation