Which of the following statements is correct?Ī) A ladder logic program is hard to analyze because it is totally different when compared with the equivalent relay logic solution.ī) The number of ladder logic virtual relays and input and output instructions is limited only by memory size. PLCs are _ designed for use in the control of a wide variety of manufacturing machines and systems.
The ladder logic program is usually stored in software#
Which of the following statements is not correct?Ī) Input and output instructions in ladder logic do not directly represent the switches and actuators.ī) The PLC rung output is a discrete output instruction or bit in memory.Ĭ) Each rung of the ladder logic represents a logical statement executed in software inputs on the right and outputs on the left.ĭ) PLC input instructions are logical symbols associated with voltage at the input module terminals. List at least five data that is held in PLC system memory. What is the difference between system PLC memory and user PLC memory? What are the four major components of a PLC device?
![the ladder logic program is usually stored in the ladder logic program is usually stored in](https://accautomation.ca/wp-content/uploads/2015/07/Sequence-Table.png)
What is the difference between a Fixed PLC system and a Modular PLC system? What is the difference between a discrete PLC input port and a variable PLC input port? Sourcing occurs when the current flows out of the PLC port and sinking occurs when the current flows into the PLC port. In half duplex channeling, the DTE transmits data to and receives data from the DCE through two separate transmission lines Simplex channeling occurs when the DTE either transmits data to or receives data from the DCE The user memory segment stores information needed to execute the user program When selecting PLCs that meet your needs, you should consider manufacturer’s support, serviceability, and programming software The arithmetic logic unit (ALU) carries out math and logic instructions
![the ladder logic program is usually stored in the ladder logic program is usually stored in](https://cq.cx/pics/ladder-sample.png)
Static RAM (SRAM) stores data in the form of charge on capacitors. One benefit of PLCs over electromechanical relay logic systems is PLCs require minor wiring and can be modified and reprogrammed within a few hours.ĭiscrete input ports are ports that are either open (off) or closed (on). The section of the PLC system memory that holds the status of discrete input ports is the _ status
![the ladder logic program is usually stored in the ladder logic program is usually stored in](https://s2.studylib.net/store/data/018721727_1-47de98c84c8e42bdf7cdbb1e4be03248-768x994.png)
The _ segment holds the ladder logic program A _ converts the digital output signals back to analog signals The four major components of a PLC power supply are a line conditioner or varistor, transformer/rectifier unit, RC filter, and _.Ī(n) _ is a semiconductor device that can maintain a steady voltage level. If all the units are in one fixed enclosure, the PLC is called a _ PLC