Hollyland Spares - Tally signal Universal Converter Remotes Controls the inner multi-core conductor paths

the inner multi-core conductor paths inside the HL-TCB03 are laid out to safely isolate the individual camera logic circuits:

Hub Interface & Studio Infrastructure Bridging

but the SSDs work on a computer and the camera's internal CFast slots work fine

You must map the accessory button inside the transmitter’s internal firmware

Hollyland Spares - Tally signal Universal Converter Remotes Controls the inner multi-core conductor pathsThe Hollyland Tally Signal Universal Converter is an essential piece of hardware designed to bridge the gap between 3rd party live production video switchers and Hollyland wireless systems (most notably the Mars T1000 and Syscom 1000T intercom grids). In live video production, "Tally" is the red green light system that lets camera operators and on screen talent know which camera is currently live ("Program" Red) and which camera is coming up next