# Interview Questions : Process control Engineer

**URL:** <https://forumautomation.com/t/interview-questions-process-control-engineer/376>\
**Category:** Instrumentation\
**Created:** [March 31, 2015, 5:21pm UTC](https://forumautomation.com/t/interview-questions-process-control-engineer/376 "2015-03-31T17:21:41Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![automate](https://forumautomation.com/letter_avatar_proxy/v4/letter/a/51bf81/32.png) [@automate](https://forumautomation.com/u/automate)\
**Post date:** [March 31, 2015, 5:21pm UTC](https://forumautomation.com/t/interview-questions-process-control-engineer/376/1 "2015-03-31T17:21:42Z")

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Q)What does PID mean? (Be specific, don’t just define the Three Letter Acronym) Q)PID is normally used for three-mode control. What does this mean? Q)What is meant by the term setpoint? Q)What is a cascade loop? Q)What is a single loop controller? Q)Discuss the interrelationship between SP, PV and Output. Q)What is a marshalling panel? Q)What is the difference between points and tags? Q)In process control, what is the function of a transmitter? Q)What is meant by the term 4 to 20? Q)What is an RTD? Q)In process control, what do the abbreviations, AI, AO, DI and DO typically stand for? Q)What is a closed-loop system? Q)What is a thermocouple and how does it work? Q)Discuss the difference between a servo motor and a stepper motor Q)What is an actuator? Give an example of an actuator: Q)Describe the function of a controller Q)What is the difference between a batch process and a continuous process? Q)What is a controlled variable? Q)What is an A/D converter Q)What do we mean when we say a loop needs to be tuned?