Objective 1& 2 Flashcards
what are the three basic components of a CONTROL system?
- input devices
- controller
- output devices
the selection of PLCs are based on?
number of input and output points (I/O) they can service
smart relays are considered to be?
smaller PLC s
PLC programs can be changed while the processor is running? T/F
true
List four advantages of PLCs over relay control?
1.lower Overall cost
2..programmability
3 .solid state reliability
4.expandability
list the four major HARDWARE components of a modular PLC system
- power supply
- backplane
- processor CPU
- input / output modules
What part of the PLC does the CPU form of?
The Processor
Three types of memory used by a PLC
- RAM (random access memory)
- ROM (read only memory)
- EEPROM (Electrically erasable programmable memory)
A data highway is a type of______?
Local Area Network (LAN)
What is the difference between volatile and non-volatile memory?
“Volatile” memory is cleared of all data if it loses its electrical power source.
“Non-Volatile” retains data and programs after the electrical source has been removed.
what does an input module do?
receives signals from sensing devices
what is a remote I/O used for?
used to reduce the amount of cabling between the PLC and I/O devices.
list the sectors of industry PLCs are involved in
- chemical and petrochemical
- automobile manufacturing
- metal smelting and mining
- lumber, pulp, and paper production
- food and beverage production
What does the acronym PLC mean?
Programmable Logic Control
what is the purpose of the BACKPLANE
it serves as the power and communication BUS for the PLC components
