plcs
Hexadecimal number system consist of ____
16 digits
A retentive timer instruction is used to monitor total accumulated time or where an operation or process requires the process be stopped or halted momentarily
true
3 types of counters
up down up/down
A ___ can be used if a control system requires remote monitoring, data acquisition of process condition, overload motion control, overloads are programmed as normally opened
pac
4 basic components
power supply CPU input/output programmer
The memory size of a word can be ___ ___ ___ or ____
8 bit 4 bytes 8 bytes 16 bits
PLC are special purpose industrial computer designed for the control of a wide variety of machines
True
____ in a PLC refers to overriding a program input value using PLC software
Forcing
HMI is _____
Human machine interface
___ provide interface between field equipment and CPU
Input modules
____ is considered valid if its a 2 state signal successfully changed from AC to DC through the bridge rectifier accepted and passed through the threshold detector successfully debounced if AC between 80 and 132 VAC
discrete signal
Reading a PLC ladder logic a bad rule to follow would be follow the ___
current
An I/O address for terminal 14 of an input module located in slot 4 I:4/14
True
____ instructions retain their state when master control instruction is executed
latch
If you want something to stay on for a certain time after system is shut off use an ____
off delay timer
_____ control pressure regulation, temperature, regulation analog valve position
analog output
3 important steps of scan time
input state execute program output state