Remote operation of the instrument is accomplished via an Ethernet interface to the S331P controlling tablet or PC. The Site Master S331P fully supports the IEEE-802.3 standard. Most Site Master functions can be controlled via an Ethernet connection to a PC that is connected directly to the S331P controller (with an Ethernet cross-over cable) or through a network. Alternatively, the user application can be installed on the S331P controller to interface directly with the S331P software.

Ethernet networking uses a bus or star topology in which all of the interfacing devices are connected to a central cable called the bus, or are connected to a hub. Ethernet uses the CSMA/CD access method to handle simultaneous transmissions over the bus. CSMA/CD stands for Carrier Sense Multiple Access/Collision Detection. This standard enables network devices to detect simultaneous data channel usage (called a collision) and provides for a contention protocol. When a network device detects a collision, the CSMA/CD standard dictates that the data is retransmitted after waiting a random amount of time. If a second collision is detected, then the data are again retransmitted after waiting twice as long. This is known as exponential back off.