PLC Chapter 6 Review Practice Test.

PLC Chapter 6 Review Practice Test. What is a programmable logic controller (PLC)? - CORRECT ANSWER a specialized computer used to control machines and process. What is the standard programming language used with PLCs? - CORRECT ANSWER Relay ladder logic (RLL) The programmable controller operates in real time. What does this mean? - CORRECT ANSWER that an event taking place in the field will result in an operation or output taking place. What is the function of a PLC interface module? - CORRECT ANSWER To accept signals from the machine or process devices and to convert them into signals that can be used by the controller What is the function of a PLC output interface module? - CORRECT ANSWER To convert controller signals into external signals that are used to control the machine or process How does the processor identify the location of a specific input or output device? - CORRECT ANSWER By its address Compare bit level and word level addressing. - CORRECT ANSWER Bit level addressing specifies a discrete device that is connected to a specific terminal. Word level addressing specifies an analog device connected to a module that uses a word of information. In what way does tag-based addressing differ from rack/slot-based addressing? - CORRECT ANSWER In tag-based addressing you use a tag (alphanumeric name) to address data (variables). In rack/slot-based addressing a fixed numeric format is used to identify the address data. Most PLC modules use plug-in wiring terminal strips. Why? - CORRECT ANSWER For ease of wiring and replacing modules