Re: IHRM Videos and DCS

["Ira Schneider" <ira_schneider@iname.com>]

I read their description of how they implemented DCS on their layout.

I think their implementation (i.e. multiple TIUs) mostly addresses the problem of
unreliable signals between the TIU and the engines.  The idea of breaking a large
layout into blocks and using separate TIUs to feed each block would certainly
improve the signal strength.

We do have some signal strength problems on our layout.  I think one thing we can
do to help the situation is to clean all of the tracks at the beginning of every day
we run.  We normally don't take the time to do that.

I don't know how to implement blocks on our layout. Obviously, we could
remove the center pins from the bridge tracks (like they did) and feed
power only through the cables,  We could also disconnect some of the
Jones plugs (I suspect we would need to make special connecting cables
to feed the ground signals and other signals across the "disconnected" Jones
plugs) to create blocks.  But, I don't know how we would feed the track power to the TIUs
stationed near the blocks.  We would have to feed the power from the TPCs
(i.e. regulated power with the TMCC/Legacy signals but without the DCS signal)
to each TIU and then have each TIU feed their respective block.  Our wiring
isn't set up to do that.  We are currently feeding power with both TMCC/Legacy
signals and DCS signals to the tracks, the cables under the layout, and the cables
which connect the corners.  We could investigate how to do this, but I am not
sure it would provide us any real benefit.

However, I think the more important problem we have is in the communications
between the handheld controllers and the TIU.  In certain venues, like the Live Oak
Civic Center, the infrastructure in the building drowns out the signal band that
MTH is using for communications.  I have seen the reference to adding an external
antenna to the TIU before, and we could investigate using that technique to
improve our signals.  Without actually trying it, I don't know how to evaluate that
idea.  The reason I don't believe breaking our layout into blocks would help this
problem is that the TIU closest to the handheld might receive the signal
(which means you could control an engine on that block) but there is still the
problem of communicating with the TIUs on more distant blocks.  Since each
TIU only controls engines on its block, you still have to be able to communicate
with ALL TIUs to be able to control your trains anywhere on the layout.

This weekend, I was using DCS on our downtown layout.  I had no problem controlling
my trains when I was standing near the corner containing the power cart.  Sometimes
when I was standing on the far side of the layout the TIU responded to my commands;
other times it didn't.  When that happened, I just walked closer to the TIU.

I also noticed at the AMRE Fall Train Show (at the Live Oak Civic Center) the
DCS system was much more reliable than in the past.  I don't have any idea
why it was working so well.  Usually in that building I can't get a signal to the TIU if I am
more than about 10 feet away.  Either they changed something or we were just in a
good place in the Civic Center and our signals weren't blocked.

We could certainly investigate ways to improve our DCS system.




Ira