can anyone help me I have a linear encoder HEIDENHAIN brand, type: AE LS 623.
I want to connect with Arduino, but I don't know the code. can the experts teach me ?? 
Please do not hijack. Thread split.
irmad:
can anyone help me I have a linear encoder HEIDENHAIN brand, type: AE LS 623.
I can't find that exact part number. Are you sure it's not 628? I did find This PDF in English. (It seems like it's a German company so if you read German there's probably more on their German website.
There's a lot of different technologies in their different models. Some look easy to use with Arduino, some will require work. It may be easiest to buy their readout box and use the Serial RS232 interface from there.
Rather than make people search, post a link to the datasheet or product page for the exact part you are talking about.