Hach HART Manuel D'utilisation page 5

Circuit diagrams for HART communication
For HART communication, refer to
Figure 5 and Table 2.
Figure 2 HART voltage circuit - externally/loop powered
1 HART module
2 Hand-held terminal (Secondary
communication device)
Figure 2, Figure 3, Table 1, Figure
3 External power supply
4 External device (Recorder/data
acquisition system)
Figure 3 HART current circuit - externally/loop powered
4,
1 HART module
2 External power supply
Table 1 Recommended resistance values for externally/loop
Power supply voltage
18–24 VDC
24–30 VDC
3 External device (Recorder/data
acquisition system)
4 Hand-held terminal (Secondary
communication device)
powered HART circuits
Loop resistance
250–500 Ω
250–976 Ω
English 5