Siemens Simatic RTU303xC Series Operating Instructions Manual page 75

Protect the antenna connector with a suitable overvoltage protection module if you install the
antenna outdoors. See section Grounding and overvoltage protection (Page 73) for
information on this.
An antenna is not included in the scope of delivery. You will find the compatible antenna in
the appendix Antennas and accessories (Page 363).
RTU3031C: Connecting the GPS antenna (XR2A1)
If you use position determination or time synchronization via GPS, connect a GPS antenna
to the GPS SMA socket of the RTU.
Protect the antenna connector with a suitable overvoltage protection module if you install the
antenna outdoors. See section Grounding and overvoltage protection (Page 73) for
information on this.
An antenna is not included in the scope of delivery. You will find the compatible antenna in
the appendix Antennas and accessories (Page 363).
Connecting up the digital inputs X20 to X23
You can connect two sensors to each of the 4 terminal blocks of the digital inputs. In total, up
to 8 sensors can be connected.
Assignment of the contacts based on the example of terminal block X20 for digital outputs 0
and 1:
● M Reference potential for inputs 0 and 1
● 0
● 1
The terminal blocks X21 to X23 are assigned accordingly, for digital inputs 2 to 7.
Figure 3-1
For the power supply of the sensors, you can use the control outputs X10 or X11 of the RTU.
Connecting the digital outputs X30 to X31
The outputs are designed as bistable electromechanical relays that switch through the signal
of the relevant connector 0 / 1 / 2 / 3 (reference potential) to the output 0L / 1L / 2L / 3L. The
switching status is also retained in sleep mode of the RTU.
The terminals 0 / 1 / 2 / 3 can be supplied with voltage via the control outputs X10/X11 of the
RTU if this is configured. You specify the voltage value of control outputs X10/X11 in the
WBM ("Operating mode" > "Power supply") for the outputs X10, X11, X40 and X42 together.
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
Input 0
Input 1
Wiring of digital inputs X20 to X23
Connecting up, installation, commissioning
3.7 Connecting up the RTU
75