You marked this solved, so I assume you figured out that the only differences between angular and linear encoder counting are that the angular encoder rolls over, and the scaling is different. Many linear encoders are actually rotary encoders mounted on rotating shafts, like a screw.
I want to be clear that I'm not trying to discourage you from asking questions - exactly the opposite. However, there's a good reason that you can't post a question on this forum without running a search first - it's quite likely that someone has already posted the same question. By using a public forum, questions only need to be answered once (that's the idea, anyway) and multiple people can contribute, which of course does not happen over private messages. If your question has already been asked, you get an immediate response - the answer is already there - instead of waiting for someone to reply. There is no advantage to sending private messages, and there's nothing wrong with asking a good question (or even a bad one, occasionally) in public. That way you contribute to someone else getting a quick answer to the same question later.
Also, from a purely practical point of view, the forum sends an email with the content of new posts in threads I follow, meaning I can simply look at the email and quickly determine if it's worth replying. Private messages are a pain because it just sends an email saying "You have a new personal message" with no information about who sent it nor what it contains, so it's hard to deal with quickly.
