Dear PJ_Glasso,
Thank you very much for your reactivity and support. I didn’t saw the techsheet doc before.
I was a little scared when I started reading your post. 
I want to connect them to S2100 because we need an easy to connect and configure professional grade solution for industrial environment (livestock). I already bought 7 x RS485 NH3 Sensors and 7 S2100 as for environment measurment not detection sensor not only for presence detection.
I still at connection stage. Their is multiple input possibilities. I’m hesitating. Besides, their is 12 V input for the data logger. Do you think that we should connect an external DC charger to the data logger ?
Thanks in advance. 
Franck 
