Hi, there! I had got GX-Developer Ver.8, which is very different from the plc programs that I have learned before. I have read many tutorials and watch it but I still don't know how to start ladder logic test. Many other people simply click on 'start or end ladder logic test' but mine was greyed. Anyone has solution? Or I just missed a couple steps of simulation? Though it is very basic problem, I will put a deep gratitude for your reply.