expanding my layout

Curious if you've considered putting the unpowered blocks under command control (e.g., using AIU ports to control on/off power with the DCS remote)...or if you're happy with what I assume is a manual control-panel with toggle switches.

I thought about connecting the blocks to the AIU but I haven't figured out if I need another one yet to finish all the connections.  I've got a box full of switches and wire to make a control panel but I like the idea of running everything through the remote, especially with the wireless option.

Note that the AIU has a 4A rated capacity, so I'd be careful using it for track power.

Well, you need to "block" the entire layout for DCS. Only the storage track and/or spurs need the toggled on/off power. I cannot determine from the diagram if you have done this. See if you can work in the 1 3/8" pieces or the 5" (6-12060) block track to create the blocks. Both have a center rail jumper wire that can be removed.

I suggest that you only use the variable output from the TIU. Simplifies the wiring. Just dial up the voltage when you want to run in Command mode. An analog voltage meter can be had on eBay inexpensively to provide track voltage information at a glance. That would also remind you to park any conventional engines left "live" as they would start to move.

Bob Miller posted:

I thought about connecting the blocks to the AIU but I haven't figured out if I need another one yet to finish all the connections.  I've got a box full of switches and wire to make a control panel but I like the idea of running everything through the remote, especially with the wireless option.

I realize this is a distraction from your primary question but I brought it up because of this recent thread on using an AIU to control block power:

https://ogrforum.ogaugerr.com/t...rack-power-using-aiu

As GRJ points out, the 4A capability of the internal AIU relays can be an issue.  The thread above shows a method of using external relays.  Since you can get suitable external relays for about $1 each, the dominant out-of-pocket cost by far is the extra AIU if you want to put all 13 blocks under individual wireless remote control.  Some talking points:

- Relays placed close to the point-of-use can simplify wiring.  That is, the current running in the control wires is a tiny fraction (a few percent) of the current that can be switched into the block.  This means the wiring to the AIU and/or control-panel can be of thinner gauge which is both cheaper and easier to deal with (e.g., soldering to toggle switch contract).

- As shown in the other thread, relays can reduce the length of track-power wiring.  While it's a your-mileage-may-vary situation, it's generally agreed that you get better DCS communication with simpler/shorter wiring patterns.   In other words, relay control wires back to a control-panel or an AIU do not carry the DCS communication signal which "rides" on the track-voltage.

- If you plan to have lighted indicators showing powered blocks/spurs/sidings, the relay method has the advantage of a fixed DC control voltage that can easily drive low-cost LEDs.

We now return to your regularly scheduled programming...

As Moonman suggests, rather than an external toggle switch to select between a fixed TIU output channel and a variable TIU output channel, you can use just the variable output channel.  Perhaps not immediately obvious but 1) you can perform DCS command control on a TIU variable channel, and 2) by setting the variable output channel to "max" it essentially behaves like a fixed TIU output channel.

Thanks to all for the replies.

I'm not real confident with the relay wiring so maybe I'll try that after I get everything up and running. My apologies for not being clear on the main question. In the OGR video there's a segment about controlling conventional engines with the DCS remote. That's where I got the idea that I might be able to cheat a little and run one set of control wires from Variable Output 1 and a second set from Fixed Output 1 from the TIU and use terminal blocks to wire them to the same track connections, then switch between channels using the remote depending on which engine I'm running. This way I could just use power bricks through the TIU & not have to worry about a separate throttle. I'm not clear on setting the variable output to "max" and still being able to use the remote for DCS  control, unless you mean using the throttle with the power brick - got to read up some more.

I know this isn't the traditional way blocks are meant to be used but in my simple mind I figured it would work. It's hard to see in the picture but I've got the 1 3/8" fastrack sections between each "block" - I've got 3 blocks on the outside loop, 2 on the inside loop, and separate blocks on each siding and the "yard loop" that feeds the 2 sidings in the center. My thought was to essentially wire it as a conventional layout, using the 2 channels as I described above, and put toggle switches on each block so I could park a switcher or two until I need it, then park the main engine on one of the outer loop blocks while I drill the cars. Probably overkill for a layout this small but I wasn't sure how else to wire it to be able to use the conventional & DCS/TMCC pieces on the same layout. I also  figured it would be good practice for the Empire Build (gotta have a dream ).

Thanks Again

Bob

I set the variable channels into fixed mode and then use them like they were fixed channels.  The good part is when I need to run a conventional locomotive, I just address one of the tracks and it drops into variable voltage mode automagically.   The next power cycle it'll be back in fixed mode until you vary that track voltage again.