TIU does not see the AIU???

I'm having same problem. I have 2 AIU's which my one TIU recognizes. I added a 3rd AIU, pressed Read, and the 3rd AIU is not recognized. I've checked for proper cables (MTH's that came in the AIU box), proper cable ends, and inserting cables into correct ports. Disconnected 3rd AIU and moved it to 1st AIU directly from TIU. Pressed Read. Remote shows one TIU and one AIU. Moved AIU back to 3rd position. Pressed Read. Remote now shows one TIU and 6 AIU's; yet I only have 3 AIU's. Disconnected 3rd AIU and pressed Read. Remote now shows one TIU and 2 AIU's. Reconnected 3rd AIU and pressed Read. Same result, 6 AIU's. Help!

Try adding the 3rd TIU---not READing it

I'm not trying to add a TIU. I'm trying to add a 3rd AIU; for which I only know how to add an AIU by Read. Is there another way?

Post deleted by author

Thanks for the responses. Let me try to clear up the confusion.

I have one, and only one TIU. I want to daisy chain 3 AIU's in a row to the one TIU. Five AIU's total is possible with one TIU, but I only own 3 AIU's. Currently I have 2 AIU's daisy chained to my one TIU. Everything (switches, accessories) works great. Now I need to add another (the 3rd) AIU to the daisy chain on the one TIU because I have more accessories I need to control. Instructions say to us cable that came with AIU, connect the cable to the 2nd AIU in the daisy chain, power up, and press Read. When I do so I'm now seeing in the Remote that I have 6 AIU's in the daisy chain; which I don't because I only own 3 AIU's. I should only see the 3 AIU's I own. I'm currently hooking up an accessory to the 3rd AIU to see if it's powered and it does anything. If so I'm going to ignore AIU's 4, 5 and 6; which the Remote shows I have, but I don't. 

OK, I got confused over your problem.  Sorry

I wired an accessory to physical AIU #3 in the daisy chain. The Remote says I have AIU's 1 to 6 from my one TIU. I electronically added the accessory to AIU's 3 thru 6 just to see what would happen. The accessory didn't work on any AIU path. The relay didn't actuate. That tells me the TIU doesn't recognize AIU #3 path, and physically there isn't AIU's 4-6.

HELP!

I read that you moved it to position one (AIU) and it read OK. My question is did you try add an  accessory while it was in that position? That would rule out a bad AIU. If it works there I would move it to the second position (leave accessory hooked to it) and see if it operates there. If yes try again in the third position. It just seems strange that it read 3 to 6 after having been in position one. By any chance do you own Barry's book? Curious if it is in there. If not let me know and I will try to look in mine as I own all his DCS and WiFi Bible's.

Curtis

Thanks for the suggestions. I'll give it a try this morning. Yes I own Barry's book. Nothing in the book about my issue. I am hoping to hear from Barry.

Dana

your going to have trouble hearing from Barry as he has passed on 

The King of DCS passed a while ago. Sorry to inform you. He is GREATLY missed. He was the MOST knowledgeable and also a good friend.

GunrunnerJohn might know as might GGG.

OMG. What a loss.

Dana

I tried AIU #3 in all positions by itself. The AIU works. Then I tried it in position #2 with AIU #1 back in position #1. AIU #3 didn't work. I tried original positions of AIU's. AIU #1 in position #1. AIU #2 in position #2. AIU #3 in position #3. When I did a Read with only AIU #3 hooked up Remote said 1 TIU and 1 AIU. When I hooked 2 AIU's together the Remote said 1 TIU and 6 AIU's. I'm running version 3.10 of TIU and Remote. I'm going to upgrade to version 6 and see what happens unless other thoughts by someone come to mind.

Dana

What Rev of TIU do you have?  In this post from an earlier thread 6 AIU's were found...and like your situation the number of "found" AIUs varied by re-powering the TIU.  

Separately, if I understand your last post, you were reading 6 AIUs with only 2 AIUs connected.  Was one of these 2 AIUs the most recent AIU which I believe you're calling AIU #3?  Apparently you've been running 2 AIUs (AIU #1 and AIU #2) successfully and without incident.  And it's just when you introduce AIU #3 into a configuration of 2 or more AIUs (AIU #3 works fine in a 1 AIU configuration) that the problem arises?  If this is the case, it seems there could be a hardware issue with AIU #3.

Running rev 3.10.  Trains have been in storage for 15+ years.

You understand my posts correctly.

What I've decided to do is take the TIU, Remote, and all 3 AIU's to an MTH repair station for software upgrade. I'm hoping software upgrade of TIU and Remote enables the TIU to recognize the 3 AIU's properly. 

I guess moot if you're taking it all in, but by TIU Revision, I was asking about the hardware revision (F,G,H,etc.) ... vs. the numerical software revision (#.## like 3.10).  I believe there's a sticker on the bottom of the case that has a letter on it.  I may be using the wrong nomenclature (version, revision, release). 

I have 2 TIUs, and only 1 connected. The sticker on 1 connected reads, " Contains FCC ID OT8RFMT." The TIU not connected sticker reads, "Rev I." I'm going to take both TIUs to the repair station.

GET THEM ALL UPDATED then see where you are. TIU, Remote and WIU (if you have one) should all be current versions. That is the FIRST thing Barry would have said I think.

That's the plan. Don't have WIU though. I'm in the process of building/wiring my layout so not too much of a problem disconnecting wires to AIUs and reconnecting after upgrade.

Thanks for all the support.

Perhaps obvious, but presumably AIU #3 is uniquely labeled.  I'm still thinking there is something about AIU #3 when used in a multi-AIU configuration.  That is, with the same TIU, AIU #3 does not play well in a 2 AIU configuration whereas AIU #1 and AIU #2 play well together.  Please post back with whatever you find.

Sounds like the wiring is not sufficient to power all the AIU's, or your aux power to the TIU is insufficient.  This is been discussed before.  If you have long runs to the AIU, the power drop for the 12VDC is too great and the AIU won't function.  I believe Marty Fitzhenry posted this diagram of how he solves this problem, an aux 12VDC supply just tapped into the cable for the more distant AIU's.

I wish distance was the problem. My layout is 12x13 feet. Few basements in Southern Nevada! All 3 AIUs are next to each other and the TIU, using the factory cables. I've also done factory resets on TIU and Remote. Going to train show in Salt Lake City next weekend. MTH repair station nearby. Dropping off all TIUs and AIUs for upgrade and daisy chain together.

Well, distance and/or wire gauge, as well as the amount of power supplied to the TIU all contribute to the issue.  If you have a AIU that doesn't work at the end of the line, but works when it's plugged in first, I'd be looking at power drops in the wiring to the AIU's.

Or a bad cable. 

Could be a TIU issue, maybe.  I do have a TIU that will not activate an AIU accessory terminal to continuous on.  Rather than try to find out why, I just connected that AIU to a different TIU

14ga wire from Z4000 to TIU. No more than 1 foot long. TIU to AIU, and subsequent AIUs is MTH cable that came with each AIU. Cables don't appear to be the defective ones MTH supplied years ago. So, I have to believe no voltage drop. I'm hoping the software upgrade next weekend from 3.10 to latest fixes problem. At least TIU and AIUs will be at MTH repair station where troubleshooting can occur. Thanks to everyone who has been trying to help me. After 15+ years in storage I'm excited to get trains up and running.

And I spent yesterday labeling wiring (20 switches and 14 accessories), and boxing up TIU and AIUs to take with me to Salt Lake City next weekend. I have many more accessories, which is why I need AIU #3.