Flow Meter Communication Protocols Explained
Flow Meter Communication Protocols Explained
The classic loop
4–20 mA with HART is the most common interface. The current loop carries the process value; HART overlays digital diagnostics and config on top, readable with any HART communicator.
Pulse output for totalizing
Pulse outputs (NPN/PNP or dry contact) drive remote counters and PLC totalizers with high resolution — ideal for batching and custody pulse pulses.
Digital fieldbus
- RS485 / Modbus RTU: best value for multi-drop networks, up to dozens of meters on one pair of wires
- Modbus TCP: drop-in for Ethernet control systems
- Profibus PA / DP: for plants standardized on Siemens systems
How to choose
| Need | Choose |
|---|---|
| Simple analog + diagnostics | 4-20 mA + HART |
| High-resolution counting | Pulse output |
| Many meters, one PLC | RS485 / Modbus RTU |
| Plant-standardized Fieldbus | Profibus PA |
All Boka transmitters include HART as standard, with RS485/Modbus and pulse as options. Tell us your loop architecture and we wire the right output into the data sheet.
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