1 August 2005
ISA Certified Control Systems Technician (CCST) Program
This question is from the Level III study guide, Domain 2, Loop checking.
Level III represents a professional who has a 13-year total of education, training, and/or experience.
All of the following are basic components of a PLC system EXCEPT:
B. I/O system
C. Power supply
D. CRT monitor
A programmable logic controller (PLC) has a microprocessor, and it controls industrial processes. It communicates with other process control components through data links, handles simple switching tasks, PID (proportional-integral-derivative) control, complex data manipulation, arithmetic operations, timing, process, and machine control-all without a CRT (cathode ray tube) or video monitor. Engineers program it and leave it alone. The correct answer is D.
Nicholas Sheble (firstname.lastname@example.org) explains the answers to CCST questions. For information about the CCST program, go to www.isa.org/ccst.