Display Management Overview
The system controls the Display Channels at two levels:
- Primary Function Level
- Channel Level
The primary function of a display will be either:
- Platform Next Train Indicator (NTI)
- Departures Summary
- Arrivals Summary
- Information Displays.
The primary function works at a level above the actual display channels. Channels on the system can be assigned to any of the above primary functions. This is achieved by the use of display sequences. Each of the primary functions can be viewed as a sequence and selected on any output channel. In this way any monitor on the system can display any information. The system can be 'locked down' so that particular displays are not allowed on certain channels, or a channel can only display a certain primary function if required. This is used to prevent Platform NTI's from being posted to the wrong platform, and information pages with non-permitted backgrounds being presented within a drivers view.
A complication at the channel level is the use of shared displays, and orientation changes. This results in the need to create more than one page layout for a particular primary function, or display more than one primary function on a display. This is managed automatically within the Display Controllers and so does not need to concern the operator. The system generates the correct automatic page from the train record for a particular channel, either with a change of orientation, or combining two primary functions as a side by side display, or a sequential set of scrolling displays. Since any number of pages can be scrolled, it is possible to include more than one train record on an NTI, such as the Front and Back train, where two trains are boarding at the same time.
In the past there has only been the need to create a single page format for automatic displays, but the range of display devices used in the Paddington system requires multiple formats. These include aspect ratio and orientation changes on raster displays. The system is capable of handling any of the above, while the operator simply posts a train to a platform, or a special notice to a group of displays.
After the complications of automatic displays, the requirements of Summary and Information channels is somewhat simpler. Any channel on the system can display any of the sequences of pictures produced at the primary level. Changes to the sequence will affect all channels currently displaying that sequence.
Whilst there may be a requirement to display a different sequence on each channel of the system, which the system will handle, it is likely that groups of channels will display the same information, reducing the workload on the operator to create a vast range of sequences. Channels can be moved from group to group simply by changing the sequence displaying on that channel.
The display format problem comes in at this stage, and the operator may be requested to produce a new version of a sequence where one has not been created for the display device configuration on that channel. In the case of a new orientation or aspect ratio, a copy of the sequence will be created with the correct pictures, where available, and an attempt made to amend any incompatible pages. The operator will then be requested to approve the changes, or manually assist in tidying the sequence, by either amending pictures or page layouts. Changes to the contents of the sequence result in a new sequence, which will be flagged if required.
The system allows for pages to be built from a large range of sources. Material from any available PC program can be incorporated, including animation sequences and real video. The real time video feeds are provided via the computer network, and can be linked to an external video player, or run from CD disks as required. These feeds are included in the sequence list as required, or can be included as a window in a generated page to appear as an insert. The use of portrait mode, requires the video feed to be rotated (by others), and would need a background page to fill the rest of the display.
External users can create sequences for the system. For example, an advertising agency can produce copy and layouts for a particular advertisement. This can be useful where the security around a product launch will prevent the release of this material until the night prior to the launch. The advertising agency could even download the material at the time of the launch, so that a 'watch this space' sequence could be updated to 'buy today'.