How do you get the UK semaphore junction (or branch) signals to work correctly so that when the junction is set for a branch line (leading off a main line), the lower junction or branch signal then operates to indicate that the turnout is set to the branch line? I'm placing the branch/junction signals at the approach to the branch line junction (as per prototype UK signalling practices for branch junctions), yet when either the main line or branch line is set on my route, only the higher main line signal operates, and the lower signal post doesn't. I have also tried using invisible signals to try and trigger the junction/branch signal but it makes no effect. Regards, Andy