Relay Ladder Logic
Before PLC's, THIS type of relay was used
ELECTROMAGNETICAL RELAYS
The brain of the PLC
Processor
The numerical range of terminal screws in an I?O bank
8-16
The process when a PLC Reads all inputs, takes all values and energizes or d energizes the outputs according the the user program
program scan cycle
RLL
RELAY LADDER LOGIC
Standard Logic Language
what is Relay Ladder Logic
supplies __?__ to the modules plugged into the rack
Power Supply
How many loads can 1 output handle
ONE LOAD PER OUTPUT
# of I/O points used
size of control program
Data collecting requirements
Supervisory functions required
future expansion
5 factors affecting memory
XIO
EXAMINE IF ON
what was the first PLC
MODICON
AC to DC
Bridge Rectifier
when a very big load must be operated, the task is relayed through intermediary relays called
INTERPOSING RELAYS
PLC software that allows the user to monitor and control the process is called what?
HMI Human Machine Interface
HMI
HUMAN MACHINE INTERFACE
name of the outer containment brackets
Rails
type of memory used in a cpu
RAM
A word can be any number of bits in length, even just one bit, but in PLCs it generally refers to a word ___?___ in length
16 BITS
a processor can be divided into 2 sections. What are they called?
CPU Section/Memory Section pg 35
LS1 LS2
LIGHT SWITCH 1 LIGHT SWITCH 2
the father of PLCs
Odo Josef Struger
Silicon ___?___ have a forward voltage of approximately 0.7 volts
diodes
back in the 1980’s when the desktop computer first began to appear, memory data was still so undeveloped that words as small as four bits were used and called a ?
"NIBBLE"
LD
FBD
SFC
IL
ST
5 STANDARD PLC LANGUAGES
LADDER DIAGRAM, FUNCTION BLOCK DIAGRAM, SEQUENTIAL FUNCTION CHART, INSTRUCTION LIST, STRUCTURED TEXT
SIC
ZERO