S331P Site Masterâ„¢ Programming Manual : General Information : Remote Operation Setup and Interface
Remote Operation Setup and Interface
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.