Siemens Simatic RTU303xC Series Operating Instructions Manual page 82

Connecting up, installation, commissioning
3.8 Connecting devices to the extension board
The extension board has two terminals "HART-OUT" and "HART-R" as well as the terminals
"L+" (12/24 V DC) and "M" for connecting HART Multidrop devices. Passive sensors can be
supplied via the 12/24 V DC terminal of the module. It is also possible to connect sensors
with their own supply. A common GND potential must be established in this case.
The HART Multidrop bus must be operated with 250 Ohm resistance to GND. For this
purpose, you can either use an external resistor or use the 250 Ohm resistor of the card or
expansion card through connection to the "HART-R" terminal.
You can find additional information in the HART Networks Application Guide, see
Bibliography /10/ (Page 389).
Figure 3-12
Figure 3-13
Figure 3-14
82
Connection of active sensors with self-supply and internal resistor
Connection of active sensors with self-supply and external resistor
Connection of passive sensors with power supply via expansion card and internal
resistor
Operating Instructions, 06/2019, C79000-G8976-C382-06
RTU303xC