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Networking Overview
Overview
A basic InfoChannel network contains at least one Designer, one Network Manager and one Player.
- Designer is used to create Scripts, which determine the sequence and layout of content.
- Network Manager is used to create Jobs, which control when and where content needs to be sent.
- The Player continuously runs Scripts while executing Jobs from Network Manager.
Content Flow
Content in InfoChannel is initially created with Designer in the form of Scala Scripts. Scripts, much like HTML, contain the text and layout information for graphics, sound and other multimedia files.
When it's ready to be sent to a Player or Players the content is published by Designer to a location also used by Network Manager. Any media files used by the Script are automatically transferred as well.
Network Manager then coordinates the transfer of the content files to the intended Player(s) according to instructions that are called Jobs.
Jobs are delivered to each Player and typically include instructions to get content files, but can also include maintenance and operational commands.
As Players complete their Jobs, they report back to the Network Manager on their status.
Content Updates
Each Player has what is considered to be its "Main Script." This is the top level Script that may include other sub-Scripts. The Main Script is the default Script if the Player is rebooted.
Content updates can either replace the Main Script or add to it. If the Script being sent is an updated version of the Main Script, the Player will download only new or changed files. Files that are no longer needed are automatically deleted.
If any two Scripts use the same content file, only one copy will be sent and kept, making efficient use of hard drive space.
Linked Content
Normally content files associated with a Script are automatically sent along with the Script to the Player. However if certain files need to be updated by a separate source (ie: a Sub-Script published from another location using Designer, or content files that are generated by other programs), the Script can be authored using a Link to that content instead of the actual file(s).
The Link is basically a placeholder that can be used in Designer to author where and when the real content will play. The placeholder will not be sent when the script is published.
A separate Job in Network Manager is used to send the real content which takes the place of the Link. The Link filename(s) must match that of the real content file(s) in order for the Player to recognize it.
Note that if all Scripts are published from the same location, Linked Content is not necessary. Just re-publish the Main Script and all updates will be sent to the Players.
A common need for Linked Content is when sub-Scripts are authored at different locations. For example, a company's employee video bulletin board system has a Main Script that includes messages from the central office and Links that will be filled in by Scripts published by local offices. The central office can use the Links to set the overall order of playback with having to get the actual Scripts from each individual office.
Another example would be a text file that is retrieved from a news provider FTP site (just another Publish Location) and updated periodically while the Main Script is running. Each time the text file is accessed, the most recently downloaded version will be used.
In multicast based networks (typically Satellite), Linked Content can be used to update content in smaller pieces since the nature of Multicast IP means all files are always sent to Players as a single block of data.
