We used a Southwire 16040T bluetooth DVM and connected it to the TMCC signal strength circuit located in the body of a piece of rolling stock which has pickups to power the circuit. Installed the Soutwire APP on a smart device and now we were able to see and record all the TMCC measurements regardless of the location on our 30' X 200" multi level layout. See below diagram for TMCC signal strength circuit & Southwire meter picture.
Bob D
Bob D