Comment Re:Power Grid Setup (Score 1) 492
Many automated systems do in fact use a "data rail" -- a series of inductive loops laid down the entire length of the guideway. Radio is more appealing for many reasons, not the least of which is throughput -- existing inductive loop systems transmit in the low hundreds of bits per second, though synchronously which is great for real time. Obviously, however, modern rail automation owners want to get advertsising delivered to you electronically on the vehicle, so there is a strong desire for vastly higher throughputs from wayside to vehicle. Radio gives us this and at the same time doesn't require a full length guideway installation, which is very expensive and adds significantly to ongoing maintenance.
As for the comments on safety, rest assured the rail industry has thought a bit about safety. It's one of the most conservative software industries in the world, and I would place it well above, say, air traffic control or power systems control in that regard. If there are any detected problems the trains stop, and in most systems that includes a faiure of two out of three seperately communicating CPUs failing to agree on a state vote.
As for the comments on safety, rest assured the rail industry has thought a bit about safety. It's one of the most conservative software industries in the world, and I would place it well above, say, air traffic control or power systems control in that regard. If there are any detected problems the trains stop, and in most systems that includes a faiure of two out of three seperately communicating CPUs failing to agree on a state vote.
