Tuesday, June 29, 2010

Relays

A relay is an electrically operated switch. Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. The coil current can be on or off so relays have two switch positions and most have double throw (changeover) switch contacts as shown in the diagram.
Relays allow one circuit to switch a second circuit which can be completely separate from the first. For example a low voltage battery circuit can use a relay to switch a 230V AC mains circuit. There is no electrical connection inside the relay between the two circuits, the link is magnetic and mechanical.

SCADA System

SCADA is an acronym that stands for Supervisory Control and Data Acquisition. SCADA refers to a system that collects data from various sensors at a factory, plant or in other remote locations and then sends this data to a central computer which then manages and controls the data.

Advanced Process Control: Bridge the Gap

A thirty-year focus on risk aversion has left a deep wound in the pharmaceutical industry. Manufacturers are still far more focused on avoiding mistakes than they are on continuously improving their processes. For many, quality is still measured more by the degree of error-free documentation than it is by fundamental process knowledge.