Unit 1: Basic Programable Logic Controller (PLC) Study Guide With Complete Answers 100% Verified.

A programmable logic controller is a specialized ___________ used to control machines and processes. - correct answer computer A PLC system eliminates much of the hard wiring that was associated with conventional relay control circuits. (T or F) - correct answer True PLC control systems are more reliable and easier to troubleshoot than relay based control systems. (T or F) - correct answer True A PLC operates in real-time. (T or F) - correct answer True The fixed I/O module configuration: - correct answer is typical of small PLC units, has no separate removable units, is limited as to the availability of modules. A proprietary PLC system allows the system to be connected easily to devices made by other manufacturers. (T or F) - correct answer False In which module of a PLC is the decision making performed? - correct answer processor module The input interface module - correct answer conditions the signal received from a field device The output interface module connects to: - correct answer load devices such as lamps or solenoids The programming device must be connected to the controller: - correct answer when entering a program, when monitoring a program The control plan stored in a PLC is called - correct answer a program This symbol -| |- in a logic ladder diagram: - correct answer This symbol -| |- in a logic ladder diagram: This symbol -( )- in a ladder logic diagram represents a(n): - correct answer imaginary coil that when energized can close an output interface contact Any change to a PLC program normally involves some change in wiring as well. (T or F) - correct answer False To operate the program, the controller is placed in the PROGRAM mode. (T or F) - correct answer False An instruction is a command that will cause a PLC to perform a certain predetermined operation. (T or F) - correct answer True During each operating cycle, the controller examines the status of output devices, executes the user program and changes inputs accordingly. - correct answer False. During each operating cycle, the controller examines the status of input devices, executes the user program and changes outputs accordingly. A PLC has no keyboard, CD drive, monitor or disk drive. (T or F) - correct answer True PC based control systems require the use of interface cards. - correct answer True Which of the following is not a criteria of classification of PLCs? - correct answer manufacturer address - correct answer a code that indicates the location of data to be used by a program, or the location of additional program instructions. control logic - correct answer the control plan for a given system; the program. input/output address - correct answer a unique number assigned to each input and output. The address number is used to when programming, monitoring, or modifying a specific input or output. input/output module - correct answer a plug-in assembly that contains more than one input or output circuit. instruction - correct answer a command that causes a PLC to perform one specific operation. instruction set - correct answer The set of general-purpose instructions available with a given controller. interface - correct answer A circuit that permits communications between the central processing unit and a field input and output ladder diagram - correct answer an industry standard for representing relay logic control systems. Module - correct answer an interchangeable, plug-in item containing electronic components. scan time - correct answer the time required to read all inputs, execute the control program and update local and remote output statuses.