Skip to main content

I have hooked TIU to 2 AIUs. When I press read on the remote, it says TIU1 found, 0 AIUs. Have checked cables to ensure proper connections made. Am using longer cables then ones that came with AIUs.   Used cables that came with AIU, same results, not found.  AIUs are new.  TIU sw v5. What am I doing wrong??? 

Original Post

Replies sorted oldest to newest

Craig,

First, ensure that the cables you have all have the clips facing the same way, up or down, when the cables are laid flat. Any cable that does not have the clips facing the same way should be discarded.

Second, make sure that all cables are 6-conductor.

Third, make sure that all cables are standard RJ12, 6 Conductor Cross Wired Modular Telephone Cables. The MTH cables are this type.

If the cables are all as specified above, make sure that you connect cables only between the TIU's AIU Input port and the first AIU's TIU Input port, and between the first AIU's AIU Input port and the second AIU's TIU Input port. If you used the wrong ports, you may have damaged an AIU.

Then:

  • Connect one AIU to the TIU using each cable in turn, until a READ command sees the AIU.
  • Repeat using the second AIU only.
  • If you can get each READ to see one AIU, then try connecting both using the cables that worked individually.

 

 


DCS Book CoverThis and a whole lot more is all in “The DCS Companion 3rd Edition!"

This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at OGR’s web store!
Barry Broskowitz posted:

Craig,

First, ensure that the cables you have all have the clips facing the same way, up or down, when the cables are laid flat. Any cable that does not have the clips facing the same way should be discarded.

CHECKED PER YOUR BOOK

Second, make sure that all cables are 6-conductor.

ALL 6-CONDUCTOR

Third, make sure that all cables are standard RJ12, 6 Conductor Cross Wired Modular Telephone Cables. The MTH cables are this type.

THEY ARE

 

If the cables are all as specified above, make sure that you connect cables only between the TIU's AIU Input port and the first AIU's TIU Input port, and between the first AIU's AIU Input port and the second AIU's TIU Input port. If you used the wrong ports, you may have damaged an AIU.

I HOOKED TO CORRECT PORTS

Then:

  • Connect one AIU to the TIU using each cable in turn, until a READ command sees the AIU.
  • Repeat using the second AIU only.
  • If you can get each READ to see one AIU, then try connecting both using the cables that worked individually.                  TRIED EACH AIU INDIVIDUALLY.

 

BARRY, THANK YOU FOR YOUR INPUT. I HAVE YOUR 3rd Edition and followed your instructions.  Can't believe I may have two bad AIUs. 

 


DCS Book CoverThis and a whole lot more is all in “The DCS Companion 3rd Edition!"

This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at OGR’s web store!
gunrunnerjohn posted:

I guess that should be sufficient.

I just dug out two AIU's, I'm not currently using them.  Just plugging them in and doing a read finds them.  I daisy-chained them and it found both of them.

Are you plugging the cable between the TIU AIU port and the TIU Input on the AIU?

Yes, plugged into correct ports. Thank you for your help 

Appears my TIU problem not reading the AIU(s) is a TIU REV L problem.   Took my AIUs to a local train store and hooked up to their TIU REV L which read the AIUs fine.   This TIU has been to MTH service twice previously.  Appears it will go back to them a third time.  It is only couple of months old.

Question: I also have an older TIU(has Proto 2 on the cover) which will not read the AIUs.  Tried with what appeared to be the same model TIU at the store, would not read the AIUs.        Are the AIUs not to be used with older TIUs??????  

Was hoping to use this older TIU as a backup.  I had bought it new years ago and recently tried to use it since I am currently building a layout.  It wouldn't work out of the box, sent to MTH twice for service and now it works ok with exception of reading the AIUs, hence wondering if older TIUs don't recognize AIUs?

I did purchase another new TIU REV L from MARIO's Trains where Joe was very cooperative in helping with my TIU/AIU problem solving even though they were not purchased from them.  I am very grateful for Mario's Trains help.  Good people to deal with.  

 

Last edited by W&W

To all - used cables that came with my AIUs, did not hook to wrong AIU ports, BOTH AIUs will not be READ/FOUND by my two TIUs,   BUT     are being READ/FOUND by the new TIU I bought and the TIU at the train store where I tested my AIUs.      Therefore appears my REV L & REV G    TIUs are bad as far as operating my AIUs.   I have an RA # to send my AIUs to MTH service, but prior to sending them I wanted to confirm whether I had bad AIUs and/or bad TIUs. Appears I have bad TIUs which need to be repaired.  

Anyone know if the TIU repair for not reading the AIUs is minor or major?

THANK everyone for their input, really appreciate help.

 

 

 

I suggest you spend a minute and look really closely at the contacts on the RJ modular connectors (on the cable and on the TIU/AIU) - corrosion, bent leafs/wipers that may be making loose/intermittent contact.  Kind of reminds me of scratchy/noisy connections on a landline telephones using RJ plugs/jacks - wiggle the connection or spray some contact cleaner on the contacts and audio quality improves. 

Then, since it appears everything else about your TIU (and the store's old revision of TIU) works, it seems to me there is an issue with the so called interface/buffering circuit that handles the control signals between TIU and AIU.  These are inexpensive 50 cent IC chips.  Of course there is a large overhead for a technician to clear the bench, open the box, confirm the problem IC, replace the part, test, etc..  To your point, I would be surprised if the TIU-AIU interface is tested following each and every TIU repair.

Finally got my existing REV L TIU to read my two AIUS, separately AND together - TIU to AIU to AIU.  Used short cables that came with the AIUs.   REV G TIU still will not read either AIU on test bench using same cables.   Not sure what I did differently today, maybe powering down XFMR/TIU/AIU after initial read of AIUs with none found, power up and they were found.   REV G TIU found 6 AIUs (couple times, but after powering down/up again then 0 found)???    STRANGE.  Apparently that TIU has a problem.

Anyway appears new REV L TIU I just bought(appears I didn't need) and exisiting REV L TIU now reading AIUs.

QUESTION: What lengths can cables be between TIU to AIU and then AIU to 2ND AIU???   My run between TIU and first AIU is 15-20 feet, first AIU to 2ND AIU is approx. 30-35 feet.      Should everything function properly at those distances?  I have three control panels(Central/Main/AUX).

Here it is.  Working with MTH R&D this has been confirmed and used.  The voltage needs to be DC.  Follow my artsy diagram and you will get it done.  My last AIU is just short of 40 feet away from the TIU.  Without this boost situation it will fire all switches with no problem.  I make my own cables.  

 

aiu 003

Attachments

Images (1)
  • aiu 003
Last edited by Marty Fitzhenry
Marty Fitzhenry posted:

Here it is.  Working with MTH R&D this has been confirmed and used.  The voltage needs to be DC.  Follow my artsy diagram and you will get it done.  My last AIU is just short of 40 feet away from the TIU.  Without this boost situation it will fire all switches with no problem.  I make my own cables.  

I was hoping you'd come along.

I finally am able to read both AIUs.  I shortened one long cable from 48' to 33'6".  The cable between the TIU and the first AIU is 14'.     Cable between AIU 1 & AIU 2 is now 33'6".    DCS remote now finds 1 TIU & 2 AIUs.    Now wiring approx 27 turnouts and hopefully everything will work.  I do have a spare TIU REV G maybe, that will not read the AIU.  I need to find someone to repair it or send it back to MTH service.

Thanks everyone for your help which has been greatly appreciated.

 

 

 

 

To all you who helped with Craigs Tiu & Aiu problem.  Adding something new a AIU to the PAHS layout we incurred some of the same problems.  8 hrs later with so much frustration I went to O Gauge Railroading Forum.  I did everything and more that Craig did and followed OGR's your's suggestions.  (check the cable when its flat and the plugs face the same direction).  I purchased a used AIU that came with no cable and ordered on line for a new one.  The MTH Cable very $.   I bought one that was half price.  Low and behold cable plugs opposite of each other.  The switch we had the wiring problems was right.  Thank you members of O Gauge Railroading Forum.

I urge anyone with trains join the O Gauge Mag or Digital.

Last edited by OGR CEO-PUBLISHER

Add Reply

Post
The DCS Forum is sponsored by

OGR Publishing, Inc., 1310 Eastside Centre Ct, Ste 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×