What are the main Difference between HART Protocol and Foundation Fieldbus used in industrial measurement devices.
HART Protocol and Foundation Fieldbus
The main advantages of fieldbus protocol over HART protocol is as follows.
- Real-time closed loop control completely digital end-to-end, from sensor to actuator
- More current for more powerful two-wire loop powered devices like radar level transmitters, multi-channel temperature transmitters, and more diagnostics etc.
- Balanced (non-grounded) signal with high amplitude for noise immunity
- Intelligent discrete devices like two-wire on/off valves
- Multiple devices on the same pair of wires reducing cable, tray, junction boxes and associated labor
- Multiple signals (per device) on the same pair of wires dramatically reducing cable, tray, junction boxes and associated labor
- Dramatic reduction of I/O cards reducing system footprint and weight
- Elimination of I/O card selection simplifying engineering
- Elimination of safety barrier selection simplifying engineering
- Elimination of signal marshalling simplifying engineering
- Easy addition of devices
- Easy addition of signals in devices
- Easy to change design to other device type: e.g. on/off valve to control valve or MOV
- Time synchronized control
- Fast control response period
- No 4-20 mA range mismatch
- No 4-20 mA current calibration skew
- Signal distortion detected
- Measurement over full sensor limit (no 4-20 mA range)
- No 4-20 mA five point loop test
- Real-time PV validity indication
- Position feedback on every valve
- Multi-channel temperature transmitters
- Advanced device diagnostics
- Centralized firmware upgrade