Yes.
Be aware that without an existing copy of the program you will not have any rung comments or variable descriptions. All you will get are ladder logic elements with addresses. For example, you'll see %I0001 associated with a contact instruction but unless you have an accurate wiring diagram you'll have no way of knowing what that input point is wired to.
Edit:
One condition on that "Yes". If it is a very old 90-30 CPU firmware version, you will not be able to extract the program using Proficy Machine Edition software. If the system was originally installed in the early 1990s you could have issues.