Hi there,
Yes the RS-485 allows a multi_drop of connections One master the Data-Logger and the NH#'s as Slaves. You basically connect Power and Grounds and Connect all the +"s together and all the (-)'s poll each unit by address for it’s data. Use the provided tool to poll or test comms.
Download.
The data sheet has all the info you need to test the first unit , connect the wires,setting Baud Rate on logger and go!
HTH
GL 
PJ 
Use the Guide to help set it up
Page 3 statup section is good.
In the end you’ll have a great multi-node Sensor network
