Question:
Is it possible to control an amplifier through third party control and receive feedback?
Answer:
Control and feedback requires implementation of the HiQnet protocol. The HiQnet protocol comprises multiple message types with large headers to achieve device discovery, session start, keep-alive, acknowledgement , session end, etc...
HiQnet third party programmer technical support guide is available at the following link: https://help.harmanpro.com/hiqnet-third-party-programmer-documentation
Here is a link on how to obtain third party control strings directly from Crown amplifiers. https://help.harmanpro.com/obtaining-control-strings-in-crown-amps
HiQnet protocol is not a public API and because of that, there is no programming support for third party devices available from Harman Professional.