This reply was originally posted by Bill on APC forums on 12/6/2013
Hi,
As QueenB wrote, with PowerChute Business Edition (PCBE) the software communicates with the UPS using either USB or Serial communication cable. You would attach the cable between the UPS and the system and then install the PCBE Agent. The Agent is responsible for the communication between the system and the UPS. PCBE also offers the option of installing the Server and the Console components. The PCBE Server application gathers information from the PCBE Agent/s and allow for global configuration of the Agent/s. Each Agent the Server is monitoring would be install on a separate system and each system would need a to be attached to a UPS via USB or Serial. The PCBE Console is the GUI to view all the Agents that are being monitored by the PCBE Server. You can also view the Agent/s individually using a web browser. To do this you would open your browser and go to https://:6547 (PowerChute communicates over port 6547)
With PowerChute Network Shutdown (PCNS) you install the PCNS Agent on to the system but you do not need to attach a Serial or USB cable. PCNS communicates over the network with the Network Management Card (NMC) that as been installed in the UPS. To view PCNS you open your browser and go to https://:6547
So, the differences are, with PCBE the UPS communicates with the Agent via USB or Serial. You can globally configure the Agent/s via the PCBE Server and you can monitor the Agent/s via the Console or a web browser. With PCNS the Agent communicates with the UPS via the network so there is no need for USB or Serial cables and each PCNS Agent is only viewed via a web browser.
If you have multiple system that will be plugged into a single UPS and you would like each system to be notified when the UPS determines it is time to shutdown then you should install a NMC in the UPS and install the PCNS Agent on each system. If you only have 1 system that you need to be notified when the UPS is shutting down then you should attach the USB or Serial cable and install PCBE Agent.