setStatus(MRID, {SpeakerCmd});
MRID – media point ID, for example 297,
SpeakerCmd – command.


List of commands:

SpeakerCmdPlay   = 1, file/link play, setStatus(MRID:30, {1, VOLUME, PRIORITY, "MIDURL"});,
here VOLUME - sound level, PRIORITY - priority, MIDURL - link to media file. Example: setStatus(297:30, {1, 120, 0, ""});. 
For reproducing from interface to the loudspeaker - setStatus(MRID:30, {1, 180, 0, "mr://INTERFACE_ID:31"}); and to stop broadcasting - setStatus(MRID:30, 0);.
For reproducing from interface to the interface - setStatus(INTERFACE_ID1:30, {1, 180, 0, "mr://INTERFACE_ID2:31"}); and to stop broadcasting - setStatus(INTERFACE_ID1:30, 0);.

SpeakerCmdStop   = 0, stop.  setStatus(MRID:30, 0);
 SpeakerCmdPause   = 2, pause.  setStatus(MRID:30, 2);.
 SpeakerCmdContinue  = 3, continue. setStatus(MRID:30, 3);.
 SpeakerCmdVolume  = 4, sound level setting VOLUME, 0-250.  setStatus(MRID:30, {4,VOLUME});.
 SpeakerCmdVolumeRel  = 5, increment/decrement sound for VOLUME value from the current. setStatus(MRID:30, {5,-VOLUME});.
 SpeakerCmdMute   = 6, sound off.  setStatus(MRID:30, {6,1})- mute off, setStatus(MRID:30, {6,0})- mute on.
SpeakerCmdBalanse  = 7, balance.
 SpeakerCmdSetUrl  = 8, URL play. setStatus(297:30, {8,""});.
 SpeakerCmdSeek   = 9, playback setting from the position specified in the command, milliseconds from track start, 4 bytes. setStatus(MRID:30, {9,0,1,0,0}); - playback starting from 256 milliseconds.
SpeakerCmdSeekRel  = 10, forward/backward winding.
SpeakerCmdPauseReverse   = 11, change of the command "pause" into the command "continue" and change from "continue" into "pause"  setStatus(MRID:30, 11);
SpeakerCmdSetSyncMaster = 32, synchronise, setStatus(MRID:30,{32,MasterSubID,MasterID_low,MasterID_hi});
 SpeakerCmdPlayingSync = 33, synchronise the reproduction on the devices, setStatus(MRID:30,{32,SlaveSubID,SlaveID_low,SlaveID_hi,SlaveSubID1,SlaveID1_low,SlaveID1_hi,...,SlaveSubIDN,SlaveIDN_low,SlaveIDN_hi});
 SpeakerCmdPlayingMove = 34, relocate the reproduction on the devices, setStatus(MRID:30,{32,,SlaveSubID,SlaveID_low,SlaveID_hi,SlaveSubID1,SlaveID1_low,SlaveID1_hi,...,SlaveSubIDN,SlaveIDN_low,SlaveIDN_hi});
 SpeakerCmdError   = 48, error.
 SpeakerCmdVolume2  = 0xfe, sound level for binding to dimmer, setStatus(MRID:30,{0xFE,VOLUME});.
SpeakerCmdSeek   = 0xFF, change of the command "stop" into the command "continue" and change from "continue" into "stop"  setStatus(MRID:30, 0xFF);

Mediapoint control PRIORITY (0-lowest level, 250-highest)
If you play with priority 1 and higher, then the interface will have priority 0. Control from the application will not work.


Byte media point status:
0 – SpeakerStatusOffsetState, 0 – off, 1 – is playing, 2 – error, 4 – pause;
1 – SpeakerStatusOffsetVolume, sound level;
2 – SpeakerStatusOffsetMute, Mute status;
3 – SpeakerStatusOffsetBalanse, balance;
4 – SpeakerStatusOffsetPriority, priority;
5 – SpeakerStatusOffsetMsDuration, track length;
9 – SpeakerStatusOffsetMsDuration, track current position;
13 – SpeakerStatusOffsetSyncMasterAddr, device address synchronised with media point;
13 – SpeakerStatusOffsetSyncMasterSubId, device SubID synchronised with media point;
14 – SpeakerStatusOffsetSyncMasterId, device ID synchronised with media point;
16 – SpeakerStatusOffsetSyncSlaveCount, number of devices synchronised with media point. If non-zero values then the devices addresses will be recorded after URL;
17 – SpeakerStatusOffsetURL, tracked URL reference.

The comment as for Multiroom tools tab in the interface:

Message: reproduction of the message recorded to the speaker (speakers) via the microphone of interface. For recording the messages select speaker (speakers), volume and press to start speaking. After recording the message press the button “stop speaking” and the message will be displayed on the selected speaker.
Synchronize: reproduction is synchronized between 2 speakers. Upon that two speakers replay media files synchronically, reproduction is managed from the speaker it is synchronized with. For stopping press “stop” on the synchronized speaker.
Move reproduction: reproduction is moved. At that the reproduction is stopped on the speaker from which it is moved. It is possible to manage the track from the speaker where the reproduction is moved.
Synchronize play list: play list synchronization.