Command for Audio Switcher

Which BLU device specifically?

There are modules in the AMX InConcert database:
https://trade.amx.com/Net/Inconcert/Devices/InConcertMainPage.aspx

You can also check out the BSS Soundweb 3rd Party Control Application Guide:
https://adn.harmanpro.com/site_elements/resources/1444_1474649586/Soundweb-London-Third-Party-Control_original.pdf

Not meant to be rude but it sounds like you need more than that..

Have you programmed a DSP before, BSS? Read the API that Rob put up a link for, its a great protocol but requires a little thought as its all in hex, has special bytes, escape sequences and checksums. It will require you to insert the ID of the DSP the ID of the DSP control object, etc.. Its a little more involved then typing in "SWITCH:3"

I mean its archaic, and annoying to deal with. But doesn't mean functionally it isn't a great protocol.

Use the module. Works great for most functionality.

Basic implementation video available on the training site: AMX Video & Control / On-Demand / Device Controller / Central Controllers / Duet | How to Implement the BSS Gateway Module. ..Or just search for Duet ;-)