Blackmagic and vMix switchers with IP Tally signal, so GPI&Tally interface is necessary for Tally function of most intercom systems. Most Naya wireless intercom with IP port support Tally signal from Blackmagic&vMix WITHOUT Tally interface. Just one networking cable is ok.

For some customers Blackmagic GPI&Tally interface is not cheap.

Some customers prefer to Naya Tally solution(BS180 with Tally lights) especially if they just have Blackmagic or vMix switcher.

Besides HDI-BS180, Naya FDI-BS340 and AFDI-BS450 also support Blackmagic and vMix without Tally interface.