Ethernet Cabling

Along with hubs came another form of Ethernet cable and connector: unshielded, twisted pair (UTP) wiring and RJ-45 “flat” connectors. These cables use multiple twisted pairs of wires instead of the coaxial cable specified in Metcalfe’s original Ethernet. The purpose of using twisted-wire pairs is to reduce magnetic...
Continue reading »

Repeaters (hubs)

Bob Metcalfe’s original design for Ethernet consisted of DTE devices connected to a common coaxial cable through the use of “tee” connectors, like this: This cabling arrangement suffered several problems. First, it was inconvenient to run through an office building, since each DTE device needed to be...
Continue reading »

Ethernet network

An engineer named Bob Metcalfe conceived the idea of Ethernet in 1973, while working for the Xerox research center in Palo Alto, California. His fundamental invention was the CSMA/CD method of channel arbitration, allowing multiple devices to share a common channel of communication while recovering gracefully from inevitable...
Continue reading »

Ziegler-Nichols Tuning method

Ziegler-Nichols open-loop tuning procedure :- The first process tuned in simulation was a “generic” process, unspecific in its nature or application. Performing an open-loop test (two 10% output step-changes made in manual mode, both increasing) on this process resulted in the following behavior: From the trend, we...
Continue reading »

On-Off control sytem

Once while working as an instrument technician in a large manufacturing facility, a mechanic asked me what it was that I did. I began to explain my job, which was essentially to calibrate, maintain, troubleshoot, document, and modify (as needed) all automatic control systems in the facility....
Continue reading »