SimTX API/Packets/StartMonitor

StartMonitor

Frame	ClientFrame, field 31
Member	start_monitor
Direction	Client → server
Session	Control, moderation
Roles	ROLE_CONTROL (authenticated), ROLE_MODERATION.
Permission	Control: the transmitter must belong to the account. Moderation: monitor.any.
Answered by	MonitorAck, then MonitorBlock frames, or Error
Answers
Defined in	control.proto

StartMonitor asks the server to stream the signal of a transmitter back to the client. The stream is the transmitter's complex baseband after the modulator and amplifier model, before the antenna and propagation.

Definition

message StartMonitor { bytes session_id = 1; int64 request_id = 2; }

Fields

#	Field	Type	Description
1	session_id	bytes	16-byte session id of the transmitter to monitor.
2	request_id	int64	Nonzero; echoed in the MonitorAck or Error.

Rules

• On a control session, the transmitter must belong to the same account as the control session. An anonymous control session cannot monitor anything. Authenticated control sessions need a control ticket, which the account service issues only to credentials with catalog.publish.
• On a moderation session, any transmitter may be monitored with monitor.any.
• Take session_id from the transmitter's own SessionStatus, or from a LiveSession.session_id in the StationList.
• Success: MonitorAck with active = true, then MonitorBlock frames. Failure: Error with NOT_FOUND (no live transmitter with that id) or FORBIDDEN (not yours).
• Not a heavy request. The stream starts with the newest samples; there is no backlog.

Examples

Complete frames, including the varint length prefix.

start_monitor (client to server, 24 bytes):

17                     frame length 23
FA 01 14               start_monitor (StartMonitor), 20 bytes
  0A 10 AA AA AA AA …  session_id = aaaaaaaa-bbbb-4ccc-8ddd-eeeeeeeeeeee
  10 2C                request_id = 44

monitor_ack_started (server to client, 26 bytes):

19                     frame length 25
D2 02 16               monitor_ack (MonitorAck), 22 bytes
  08 2C                request_id = 44
  12 10 AA AA AA AA …  session_id = aaaaaaaa-bbbb-4ccc-8ddd-eeeeeeeeeeee
  18 01                active = true

See also

• Monitoring a transmitter