There are also 30-minute original request programs, and a series of documentaries on pandas produced by China Central Television. Hu Zhanfan, head of China Central Television, said the website is a gift to people around the world who love pandas and crave peace, according to the China Daily.
What are PLCs and how do they work? PLCs are often defined as miniature industrial computers that contain hardware and software that is used to perform control functions. A PLC consists of two basic sections: the central processing unit (CPU) and the input/output interface system.
Relays are used to isolate one voltage level from another. A PLC may be used to control the operation of a medium-voltage motor, perhaps 2,300V or 4,160V. A relay is used to energize the starter, which, in turn, switches the motor voltage while the PLC controls the relay.