UpdateFeed

{
  "command":"UpdateFeed","index":7,"name":"Primary feed","module_name":"sct_feeder",
  "description":"Production prices","config":{"host":"feed-2.example.com","port":9000},
  "enable":1,"mode":0,"timeout":120,"timeout_reconnect":5,
  "timeout_sleep":60,"attemps_sleep":3
}

This is a complete replacement: all fields are required. Success returns {"data":"OK"}. Mapping records remain unchanged.