Hex and binary number

Dear all,
I have basic plc question.
Why we use hex or binary numbering in plc programming?
Can we use decimal instead?
Appreciate for your respons!

It seems that you have not had the opportunity to study basic digital processors which are at the heart of computers and PLCs. They store numbers in groups of bits. The most efficient storage of numbers is using a base which is a power of two. Groups of bits which have been used are 4, 8. 16, 32 and 64. None of these store the value 10 as a basic unit. Thus you see binary (single bits used one at a time) and hexadecimal (bits used 4 at a time). These are used for the most efficient and fastest processing. Some PLCs have BCD (binary coded decimal - 4 bit groups limited to the values 0 - 9) available to enable compatibility with much older applications. This is at a cost of much slower processing and decreased efficiency.

Following up on what Bernie said.

All microprocessors process bits as Bernie mentioned.
Most PLC programming software will allow you to enter and view numbers in decimal but they will always be translated behind the scenes to binary.

Some PLC programming software will allow you to change how you view numbers with the most common display modes being decimal and hexadecimal. Many also have binary and octal (base 8) display modes.

What is important to understand and sometimes confusing is that the number in the PLC doesn't change when you change the display mode. Only how you view the number changes.

http://accautomation.ca/what-everybody-ought-to-know-about-plc-programmable-logic-controller-numbering-systems/

The above link will review the numbering systems in PLC's. Just like the other two answers, everything is stored in binary. It is the interpretation of the instruction which will determine the meaning.

Regards,

It is because when looking on a PLC you will see divisions of the I/O sometimes even 16 so you have %IX3.0 and %IX3.6 up to 15
8 bits we put in HEX.
and yes it is complicating and for me i try it to keep it simple.
maybe slower but simpler.