Lesson 3 - Principles of Process Control SAQ
This lesson allows you to test yourself on the material covered in the Principles of Process Control lesson and determine the level to which you have met the learning outcomes.
Self-Assessment Questions
1. * A standard analogue signal reads 4-20 mA. What does this indicate? Why do we not use 0-20mA?
2. ** What is the difference between analogue and digital output and analogue and digital communication? Give examples of each. Which category does HART fit into?
3. ** An automated process control system fits into a hierarchy. Each level has a specific focus and a relationship to the components that comprise that particular level.
Describe the purpose of the following components and state the level at which they occur within the hierarchy:
a) The SCADA system
b) A paddle switch at the bottom of a bulk grain silo
c) Ladder logic
d) A flow controller
4. ** Compare PLCs and PCs in regard to their process control. Which would you recommend for a small brewery? Would your recommendation be different for a large, complex, fully-automated brewery?
5. ** Discuss the advantages of using VSDs compared to either not using them at all, or to using mechanical means with which to control outputs.
6. ** What is meant by fieldbus protocol and conventional wiring? Compare the two systems.