HControl (AMX / HARMAN)
HControl is HARMAN Professional's current vendor-published control API for supported AMX / HARMAN devices. In the currently published AMX / HARMAN documentation reviewed here, the normal direct API listener is TCP 4197, registered with IANA as hctl / Harman HControl Protocol, and exposed in multiple family docs as a text-based JSON-like command model using get, set, exec, and event-oriented behavior depending on the device family. IANA also registers hctl on UDP 4197; treat that as discovery/enrollment support where the selected HControl workflow actually requires it, not as the main command session. HControl is not media transport, not a neutral cross-vendor control standard, not a security model, and not a blanket replacement for every AMX / HARMAN service in a firewall schedule.
Scope: HControl (AMX / HARMAN) — select the deployed product/version; optional services require separate selection.
protocol · Catalog reviewed 2026-09-27
Infrastructure Requirements
- Supported AMX / HARMAN device family with native HControl
- IP reachability between controller/app and the target device
- firewall allowance for the actual listener, commonly TCP 4197 / IANA service hctl on currently documented families
- the exact published HControl descriptor or protocol document for that device family
- correct HControl identity / Instance ID mapping where the integration path depends on device enrollment
- integration logic that can cope with typed values, enums, normalization in returned values, and event subscriptions rather than assuming every endpoint behaves like a flat REST API
- and security policy / firewalling aligned to the actual service exposure of the chosen family. Current published AMX / HARMAN documentation for MUSE, CE, Varia, selected SVSI, CloudWorX, and newer Soundweb OMNI / AVX workflows keeps pointing to 4197 as the HControl service boundary, but the exact path tree, discovery behavior, encryption posture, and feature surface remain family- and software-version-specific.
Network & Physical Requirements
| Port / allocation | Transport | Connection / signal flow | Feature and requirement | Evidence |
|---|---|---|---|---|
| 4197 (default) | TCP | Control application → HControl device | Profile requirement · Core HControl device API AMX/HARMAN devices supporting HControl | Source checked 2026-09-27 AMX device port inventory |
Gotchas & IT Notes
- ⚠Confirm supported product/firmware, authentication and message framing. UDP discovery is not a universal HControl requirement.