It will possibile to change DM value from arduino to plc?

Hi guys!,
i have a question.
I have a OMRON PLC CJ1M CPU21… i want to know if is possible to make or change data memory (DM) from arduino to plc.
my project consist in a CNC cut.
for knowing the real position of my axis i need of incrementale encoder.
In the market there aren’t solution to encoder for nema 17 motor. however i would to think to buy 5v rotary encoder by Ebay. This linked with arduino.
Arduino will send the real valor from arduino to plc. it will be possible??
thank you for the time.
bye byeyou for the time.

If that old link does not solve the problem you need to give details of how one communicates with the PLC you are talking about. Perhaps a link to its datasheet.