Hot Air Standby (Reserve) System

The system consists of the two workstations; each of them has DjIN On Air application running with X-Player and Hot Air Standby module. Workstations have non-equal rights: one is preconfigured as Main, another - as Reserve. Both workstations are interconnected to each other through dedicated (additional) network cards by Crossover Ethernet cable. This connection (hereinafter referred to as "Watch connection") is used for monitoring of status of paired workstation. It is strongly recommended to use direct cross network connection without any additional switching Ethernet equipment.

Software part of Hot Air Standby System could be divided into two parts: Hot Air Standby module and Playback module (X-player).

Hot Air Standby module provides:

* Manual changeover of airing from Main workstation to Reserve by controlling of on air module:

* Workstation, which is quitting, stops airing

* Workstation, taking over, starts airing

  • Automatic changeover to Reserve workstation in case of failure of Main workstation
  • Generation of control commands, necessary for workstation changeover (GPO, routing, control of equipment, indication etc.)

Let us consider the system of the two modules in normal operation: DjIN application is running on both workstations, Watch connection is established. Both workstations in such conditions are treated as a single system with common logical state. Description of status of the system is provided in the table below.

State Comment
Main Main station is on air.
Reserve station is standing by.
Main mode of operation.
Reserve Reserve station is on air.
Main station is standing by.
Reserve mode of operation
Off Hot Air Standby module is switched off, workstations are functioning independently of each other.

X-Player modes of operation

Application behaviour at changeover depends on the mode of operation of the player on the taking over workstation. It does not matter, which station is taking over: Main or Reserve. Application behaviour is identical in both cases. Let us consider behaviour of station which is taking over in each of the 3 modes:

Mode Behaviour Changeover to airing
Auto Auto mode of operation, when the X-player is paired with Hot Air Standby module, works differently. When Auto mode is switched on at the standing by station, airing does not start. Instead of it player is monitoring playback position of airing station. Manual control over the player is blocked as usually. This is local, non-attended waiting mode, which does not need participation of operator.
Only this mode provides Reserve workstation to be in Hot standby condition which will result in taking over at the failure of the Main workstation.
Airing starts at the same position, where the Main station has been. So, this is "On the fly" changeover. Then player continues to work in *Auto *mode.
Live Player is controlled by operator who is responsible for loading of element into the player.
Player is not monitoring playback position of airing station.
Player start playing back first element from the queue and continues to work in full accordance with *Live *mode.
Man Similar to Live. Player DOES NOT start playing back and continues to work in full accordance with *Man *mode.

Behaviour of "quitting" workstation does not depend on the mode of the player which was airing: on quitting and changing to waiting mode player of "quitting" station will be always placed to Auto - waiting autonomous mode.

System Status Indication

System status indication is provided at the Hot Air Standby module and partly is combined with manual controls of airing station changeover.
Example of the window of Hot Air Standby module.

Module indicators:

* Indicator Main station/Reserve station - M or R in the upper left corner.

* Status of Watch connection to another workstation. Status is shown as a text string.

* CONNECTING… Connection to another module is in the process to be established.

* CONNECTED System is ready for changeover.

* ERROR, error condition is highlighted with red background. This is the situation, when Hot Air Standby system is on, and there is no connection to another workstation.

* *CHANGING OVER *means that status is in the process of being changed. Status change commands are ignored untill changeover is finished.
Highlighted by yellow.

* BUSY, means, that changeover could not be done right now. Such status of the system may result only if one Reserve workstation is used together with several Main workstations, and reserving mode is Exclusive (see below). Obviously, only one Main workstation at a time could be reserved.
Highlighted by yellow.

  • Current status of the system: Main, Reserve, Off.
    System status indication does not depend on the station: it is the same on both stations and it is showing status of the system, which consists of 2 workstations.
    Button, corresponding to active mode, is highlighted, while other buttons are backlit with grey. "Off" button backlit color is light grey or white.
    Backlit color of "Main" and "Reserve" buttons depends on X-player mode at the standing by station.
  • Player mode at the standing by station. If the player at the standing by station is in *Auto *mode, active button is highlighted by the green color (like showed above), otherwize it is highlighted by the yellow color.
Color Status
Green Standing by station is in *Auto *mode.
Changeover will happen "on the fly", playback position will be kept.
Yellow Standing by station is NOT in Auto. Changeover is controlled manually.

Single Reserve workstation for several programs

In such a case several Reserve modules are present in Reserve workstation configuration. Each of these modules has association with its own X-Player.
Such workstation could work in one of the two modes:

  • *Independent
    *Each pair "Reserve module - X-Player" is working completely independent of other pairs.
    Such mode imitates several independent Reserve workstations. The difference is in the fact that all software physically is installed on a single computer.
    Computer should be equipped for parallel airing of several programs accordingly.
    This mode is used in case of complete automatic operation of Reserve workstation.
  • Exclusive
    Only one program at a time could be changed over to reserve. If any Reserve module starts airing, the workstation will be busy and reserving of other workstations is suspended up to the time, when the failed Main station takes over again and Reserve station is standing by. This is indicated at Reserve modules of other stations.
    So, when Reserve station quits airing, it again turns on to the Hot Air Reserve for all stations.
    This mode could be used when a single reserve studio is servicing a number of On Air studios. If *any *of Main studios fails, Reserve studio will take over it including manual work of operator with mixer console, sources etc.
    On reestablishing of Main studio functionality it takes over airing, and Reserve studio is standing by for the next failure of any of the Main studios.

Mode of such Reserve workstation is configured through the settings of Reserve module at the Reserve station only.

Manual changeover

Manual changeover is possible by clicking inactive (not highlighted) button. In the result, airing is immediately changed over to a corresponding workstation.
Manual changeover could be done from any working place.
Apart from that, you can switch Auto mode on the waiting workstation. Just click the button highlighted by the yellow color. At that X-Player on the waiting workstation will be set to Auto mode and the button will be highlighted by the green color.

Manual changeover from the X-Player is impossible. If you set Live mode at the waiting station and press Play button of the X-Player (or start X-Player remotely by Fader Start signal), player will start playback to configured audio output, but system status is not changed and changeover will not take place.

Lock of Manual changeover

To avoid occasional changeover by a so called human factor you can block user from manual switching the mode.
Thus, manual changeover will be possible only when it is unlocked.
You can lock and unlock manual changeover by clicking a button with the symbol of padlock.
Icon with green open padlocklock_off.PNG blocks it.

Next option allows to set Set lock automatically on changeover.
If this option is turned on, manual changeover will be locked automatically on each change of the mode of operation. Accordingly, each next change of mode manually should be allowed evenly. If this option is turned off, you may lock manual changeover by a click on corresponding button.

Lock of manual changeover function is switched on by an option *Enable Lock function *in the settings of the module.

Remote control

Changeover could be done by a hot key, or by remote command which can be configured in the *Customize keyboard dialogue.
*You can assign remote control commands to changeover event. Each state has a corresponding indicator. One more indicator shows error condition. (click here to see more details about indicators).


Settings dialogue is opened by clicking ‘…’ button.
When configuring TCP connection you should set IP address and port number. Reserve workstation is always server, while Main station is client.

Hot Air Standby module description in VID file

Hot Air Standby system operation is provided by a bundle of the 2 modules: Hot Air Standby module and X-player module. Hot Air Standby module is created by CREATE_OBJ_MAIN or CREATE_OBJ_RESERVE command. In both cases the same module is created. In the first case this module is considered as main module, in the second - as reserve. You can change that later in the settings dialogue.

Creation of Hot Air Standby module:


Associate Hot Air Standby module with X-player:


Typical applications
h3. Temporary changeover to Reserve on the fly

Initial state: mode=Main, at the Reserve workstation X-player=Auto.

Press Reserve button to changeover to Reserve workstation on the fly. Status indicator will change to Reserve. Then you can close Djin application at the Main workstation e.g. for software upgrade or you can completely shut down Main computer for maintenance work.

Changeover back to Main on the fly

Upon finishing of maintenance works at the Main workstation you can switch it on in the same configuration as before (means, Hot Air Standby module configuration was not changed during maintenance works). On starting of Djin and establishing Watch connection to Reserve workstation, Hot Air Reserve module will show Reserve state. X-player at the Main workstation must be in the Auto mode (Reserve button is highlighted with green).

By clicking non-active Main button you can perform changeover back to the Main workstation.
On establishing of Main state, you can set X-player to another affordable mode of operation.

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