@Engineer-Joe posted:To add to all this for clarity:
The reason you want the TIU with the built in USB, is that is a version "L".
That unit has the best signal output. Any older TIU can be updated to DCS 6.1. So that alone doesn't mean it's a version "L".
The (older) product number 50-1003 that was used for years, doesn't determine what version you'll get.
I’m still confused. Seller says no USB but has RevL on bottom of TIU.