MTH TIU Read Function Location Via Smartphone Location

https://mthtrains.com/sites/de...ction/50as13515i.pdf

AKA "READ" function

Also catch22, you need the upgrade license to access certain features

In order to buy the update license, you need your device not connected to the WIU interface WIFI, but to most likely your internet connection, buy the app upgrade, and then switch back to the WIU WIFI.

Vernon, thank-you that was very helpful, but with the refresh/read function and the upgrade, TIU will still not recognize the AIU.  The AIU and cable are new out of the box, the TIU and wifi are used but the MTH engine operates with access to all features. I've double checked the connection points of the cable and the transformer input is connected to the TIU via fixed input 1.  The output of the transformer is 13.8 volts.  Any suggestion as to what else to try or other trouble shooting stuff to look at?  Unfortunately, I have no known working TIU or AIU to swap to troubleshoot the connection.  (In Cleveland, Ohio if someone wants to help.)

#1 Ensure your TIU and WIU are both fully updated to the latest firmware.

#2 I do not use the AIU on my layout, however, to troubleshoot and understand I bought one for testing and playing around. Point being, I would ensure and use a good 2-3Amp 16 or more volt supply to the TIU aux power in jack and not depend on "borrowing" power from fixed 1. Why? Because the AIU is relays that draw power, and it ALSO is 12V regulated power. Only giiving the TIU 13.8V on fixed one, that has to go through diodes for rectification and thus if input is only 13.8 you might not have enough headroom to regulate 12V for relay power under load.

#3 It did take the AIU being plugged in and then everything, WIU, TIU, powered up to get it to fnally acknowledge the AIU. Further, again, the WIU and the USB connection to a rev L tiu, can provided limited power for the TIU logic. I'm saying this is how you fail to properly reboot or power cycle a TIU logic, because you leave the WIU powered up and plugged in via USB. So again, power cycle everything while connected to the AIU.

Thanks again - likely would not have figured this out without you advice.  It was the voltage issue.  I connected the 13.8 voltage from the transformer to the track to TIU fixed voltage 2, and connected the 18 volt output of the transformer to the TIU auxiliary input.  At that point the refresh feature on the smartphone located the AIU, the connected switches could be found and operated.  I believe everything now works properly.