Networked Display Controller

Created by: Administrator, Last modification: 28 Jun 2015 (23:45 BST) by Lester Caine


The basic network display controller runs as a slave to either a master control system or a local distribution server. It is designed to provide up to 8 channels of display information working from an internal sequence diary. The use of this diary approach allows the system to be downloaded via a dial-up connection, and left to 'fend for itself'. At any time the display sequences can be overwritten as required. Also to assist in the reduction of network traffic, the controller stores local information at various levels which can be used to build new display pages in real time. The main use for this facility is to download compressed text information which the controller converts to the required screen format. In systems where a number of screen formats are required, on the raw information needs to be distributed, reducing the load on the main control system.


Multi-channel display controller The unit is built into an industrial chassis that provides the following basic mechanical resources:- *highly efficient 300-watt power supply which has UL, CSA, and TUV approvals. *19-inch Rack Mountable case which meets the EIA RS-310C Standard. *Rugged, steel chassis suitable for industrial environments. *14-slot passive backplane which meets the slot requirements for large scale computer systems. *Easily maintainable disk drive bay which allows mounting of 3 half height drives from the front panel. *Shock Mount assembly for the disk drive bay. *Lockable door for protecting the three disk drives against dust. *One keyboard connector behind the lockable front door and another keyboard connector at the rear on chassis. *Power-on switch with power indicator and reset switch behind the lockable door. *Three Cooling Fans which dissipate heat in the chassis. *Replaceable and easy-to-clean fan filters. *Specially designed adjustable hold-down clamp which protects plug-in cards against vibration. *Passive Motherboard The case takes a PCI Bus passive motherboard which provides a processor slot and 12 slave PCI slots. This allows repair and maintenance of the system to be improved as the processor card can be replaced if required.

Basic Configuration

The basic controller configuration is determined by the current limitations of Windows 98. This provides a supplier independent multi-screen display management, but is restricted to 9 display cards. (Rather than the 32 limit of the older graphics system). Eight slots are allocated for channel graphics cards, whilst a ninth card provides the local engineering display. The slot closest to the processor card is allocated to a 10/100BaseT network card. This leaves two spare slots which can be used for either a sound channel, or additional control equipment. !Processor Card The basic system is fitted with a K6-233 processor with 64Mb of Ram and has provision for an on board ROM disk if the unit is required to run without additional hard disks. Since no local control is provided both serial ports are available for external use. These can be board configured to support either RS232 or RS485 as required, removing the need for additional cards or interfaces to connect to Slave LED and dumb Displays that can be supported off the controller. !Graphics Cards By changing from a bespoke graphics system based on Multi-channel ISA graphics cards to Windows 98, the whole range of PC graphics cards are available. This removes many of the problems of ongoing support for the controller, but does require careful management. At present graphics cards from ATI have been adopted for the basic controller. These provide both RBG and Composite Video outputs that allow flexability in channel configuration. Each channel can be configured to its own display standard, allowing both monitors, and plasma displays to be configured on the same controller. The setup of channels is then stored in the sequence management software, where appropriate display pages will be selected as required. With the increasing use of portrate mode, the controller will also manage the correct aspect ratio for the display channel resolution selected. A number of other cards are available with additional facilities. An enhanced version of the card selected provides a composite video input and handles all of the control necessary to include this as a resizable window within the output picture. There is no provision on currently available cards to provide a picture rotate to output this local video feed to a portrait mode monitor, however if the picture is rotated prior to being input, this problem can be overcome, with a lose of resolution as 768 pixels are reduced to 576 on the input signal ( the actual output picture may be lower resolution still). !Video Support There are a number of ways to support video within the system, in addition to the direct input to a particular graphics card. As the controller is networked to the main system, intranet video streaming provides a means of carrying live video around a large system. A software package from RealMedia provides for the management of up to 60 live video feeds from a server system to remote display devices. These video feeds are normally provided from CD or DVD sources where the video material has already been compressed for use, and in which the rotation of the picture for portrait mode can be included. The use of live inputs requires the addition of a graphics card that provides hardware compression in real time. While these are currently expensive items, only one or two are normally required as once the tape has been processed, it is stored within the master system for reuse later. In addition to streaming video information, RealMedia provide an animation system that takes presentation graphics and outputs them in a similar manor. Advertising material can be created by the agency using their preferred tool, and passed electronically for display on the system. !Integrated Software The display controller software is built around a sequencer. For each channel, a sequence of pictures is selected. The active sequence is selected from a time list which can be a full calendar if required, but in the basic system is a simple 24 hour table. The displaying sequence can be changed in two ways, a global request for a sequence to all monitors, or a toggle to an alternative sequence. The global function has the additional complexity of managing displays of different formats, but this is handled by ensuring that the sequence selected has a version for each format required on the system. The one name will be used, but the display controller will select the correct version for the display type, and orientation of that channel. Where a version is not available, the master version will be used and the appropriate page generated as required. The additional Toggle function allows for such situations as posting to a station platform, with a default sequence when nothing is posted, or Opening and Closing a Checkout or Channel. This allows the addition of simple local control buttons or switches for this function if required. This function can also be used to provide a local, train or bus departed, or a Next function on counter systems. There are a number of ways that pages for the system can be managed. The simplest page will be a raw static picture of the correct size for the output channel. This can be enhanced with animation sequences such as flashing and scrolling, and will be displayed for a fixed time. In addition, text pages can be displayed, using an HTML type format that will build a page using fonts, clip art and live video streams. The sequencer will select and build these pages as required. The third type of page is refered to as an automatic page. It uses the same page layout format as the text page, but the text is filled in from a central database of information. This allows the creation of NTI and Summary pages, or waiting tables and room usage displays automatically from a master management system. This removes the major problem of display management from a server system, and ensures that displays of the correct format are output as required.

Network Operation

While it is envisaged that the the display controller will be linked back to a main system via CAT5 cabling, the long distances invloved in some installations will require the use of Coax or Optical Fiber links in some situations. This can either be managed via a change of network card, or the addition of a local hub which may support more than one local display controller. This is a matter for the network system design. !Summary The basic display controller provides:- *8 Channels of display information. *RGB, Composite Video and SVHS outputs. *Display on Monitors or Plasma Displays *Selection of Mode and Orientation an a channel by channel basis *10/100BaseT Network connection *Local management of additional controls *Serial link to alternative display devices (LED or DVC) *Serial link for additional control of display devices *Local or network support of live video *Stand Alone operation for dial-up situations *Rugged 19" Rackmounted or Freestanding Case !Support Equipment In addition to the main controller, a 2U Rack can be supplied that provides for the distribution of signals to a number of display devices from each channel. Up to 8 monitors can be driven from each channel in multiples of two channel drive cards. In addition, for simple systems, an external video source can be routed direct to the monitors by-passing the controller. This is selected via the display controller, and defaults to the external input if the controller fails.