Thank you Jim Fin and Ron Ron.
Ron you have basically described what I have, I do not have the Ultima.
I have a 5.3m x 3.5m shed. I have run a bus line cable with extensions on to connect 4 loops in about 6 locations around the loops (circuit). I have placed one Command Station at one end and power with the IR sensor on top. The other end has the Pro Box, with a Command Station on top, and a IR sensor on top of that. Power and track connection. I power up, place a loco on a length of track and select the loco address but the hand set keeps showing the Stop icon and Short icon. This also happens when I set up a small length of track, and connect a Command Station only to the track, again the Stop and Short icons keep appearing on the handset. I disconnected the Dynamis system and put a Hornby digital control on same scenario, single length of track. Put the loco address in and nothing happens, no movement or no sounds? I have tried several locos to both systems but nothing working. The Dynamis was working on an independent piece of track used to test the locos and it worked then. For some reason I cannot find the Dynamis IR extension, I had a few weeks ago but I have put it in a safe place.
Any help/advice to solve this problem would be much appreciated. Many thanks.
Regards
Russell