18 of 19 Program Example Escalator Control

    18 of 19 Program Example Escalator Control





    01 of 19 Introduction
    02 of 19 What is Sequence Control
    03 of 19 Performing Sequence Control
    04 of 19 Wiring Training
    05 of 19 Wiring Diagram, Sequence Diagram
    06 of 19 What is PLC
    07 of 19 PLC Structure
    08 of 19 PLC Wiring
    09 of 19 PLC Program
    10 of 19 GX Works2 Operation
    11 of 19 Starting the Software and Screen Structure
    12 of 19 Program Using the Function Key
    13 of 19 Writing a Project to PLC
    14 of 19 Checking the Operation
    15 of 19 Sequence Instructions
    16 of 19 How to Program
    17 of 19 Program Exercise
    18 of 19 Program Example Escalator Control
    19 of 19 Ending

    A programmable logic controller (PLC) or programmable controller is an industrial digital computer which has been rugged and adapted for the control of manufacturing processes, such as assembly lines, or robotic devices, or any activity that requires high reliability, ease of programming and process fault diagnosis.

    PLCs can range from small modular devices with tens of inputs and outputs (I/O), in a housing integral with the processor, to large rack-mounted modular devices with a count of thousands of I/O, and which are often networked to other PLC and SCADA systems.

    They can be designed for many arrangements of digital and analog I/O, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed-up or non-volatile memory.

    PLCs were first developed in the automobile manufacturing industry to provide flexible, rugged and easily programmable controllers to replace hard-wired relay logic systems. Since then, they have been widely adopted as high-reliability automation controllers suitable for harsh environments.

    A PLC is an example of a "hard" real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result.