Operating Manual    Compact Weather Station 
  G. Lufft Mess- und Regeltechnik GmbH, Fellbach, Germany  23 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 6: Connections 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8  Connections 
There is an 8 pole screw connector on the underside of the equipment. This serves to 
connect the supply voltage and interfaces by way of the supplied connection cable. 
 
Equipment connector: 
 
  View on sensor connection 
 
Pin assignment: 
1  White  Supply voltage ground 
2  Brown  Positive supply voltage 
3  Green  RS485_A / SDI-12 GND 
4  Yellow  RS485_B / SDI-12 Data Line 
5  Gray  Jumper for activation of SDI-12 mode 
6  Pink  Jumper for activation of SDI-12 mode 
7  Blue  Heating voltage ground 
8  Red  Positive heating voltage 
The cable marking is in accordance with DIN 47100. 
Note: The yellow protective cap must be removed before plugging in the equipment. 
If the equipment is not connected correctly 
-  It may not function 
-  It may be permanently damaged 
-  The possibility of an electrical shock may exist 
When connecting the heating voltage the correct polarity must be strictly observed. 
Wrong polarity of the heating voltage, as well as wrong polarity of the supply voltage 
will cause damage of the instrument. 
8.1  Supply Voltage 
The supply voltage for the compact weather station is 12 - 24V DC. The power supply unit 
used must be approved for operation with equipment of protection class III (SELV).  
8.1.1  Limitations in 12V mode 
If the heating is operated on 12V DC, account must be taken of the functional restrictions in 
winter operation. 
Note: A heating voltage of 24V DC is recommended to guarantee full heating duty. 
8.2  RS485 Interface 
The equipment has an electrically isolated, half-duplex, 2 wire RS485 interface for 
configuration, measurement polling and the firmware update. 
See page 35 for technical details.