What is a programmable logic controller?

What is a programmable logic controller?

A programmable logic controller (PLC) is a special form of microprocessor-based controller that uses a programmable memory to store instructions and to implement functions such as logic, sequencing, timing, counting, and arithmetic to control machines and processes and is designed to be operated by engineers with perhaps a limited knowledge of

What are programmable logic relays (PLRs)?

In more recent years, small products called programmable logic relays (PLRs) or smart relays, have become more common and accepted. These are similar to PLCs and are used in light industry where only a few points of I/O are needed, and low cost is desired.

How many answers do you have for 102 programmable logic controllers?

102Programmable Logic Controllers ProblemsQuestions 1 to 19 have four answer options: A, B, C or D. Choose the correct answer from the answer options. 1 Decide whether each of these statements is True (T) or False (F).

How do the 198 programmable logic controllers move?

For the rung shown, when there is an input to | | in the rung, the 198 Programmable Logic Controllers move occurs from the designated source address to the designated destination address.

Welcome to Module 24, which covers Programmable Logic Controllers, or PLCs. The Programmable Logic Controller (PLC) was invented in the 1960s to replace the sequential relay circuits traditionally used in machine control. A PLC is a solid-state, electronic device that controls the operation of a machine.

How does a timer work on a 160 160 programmable logic controller?

160Programmable Logic Controllers 9.2.1 Sequencing As an illustration of the use of a timer, consider the ladder diagram shown in Figure 9.5(a). When the input In 1 is on, the output Out 1 is switched on. The contacts associated with this output then start the timer.

What is looping in logic controllers?

212Programmable Logic Controllers 3Looping A loop is a repetition of some element of a program, the element being repeated as long as some condition prevails. Figure 13.4(a) shows how this can be represented by a flow chart. As long as condition X is realised then the sequence A followed by B occurs and is repeated.

What is a PLC controller?

Central heating system with PLC controller The programmable logic controller dates as far back as 1968 when General Motors set out to find a new technology to replace their hard-wired electromechanical relay system with an electronic device.