Talk:Solid State Interlocking

PCM v TDM
Isn't PCM a method of conveying analogue signals within a digital environment?7severn7 (talk) 12:55, 12 January 2010 (UTC)

DLR
I am not sure if the initial DLR system from Tower Gateway used SSI or a variant thereof, but they changed to Seltrac by SEL Alcatel, now Thales, to change from fixed block to moving block. 92.200.132.198 (talk) 14:22, 21 March 2023 (UTC)