Modern control systems for LED screens
Generally speaking a control system includes a source of video information on the high level (PC, specialized player), a software, a set of controllers that ensure data feed and conversion, and LED drivers connected with controllers into a single network and transferring digital signal into current forwarded to LEDs.
Control system is a link between numerous subsystems of a LED screen and the actual image that we see on a screen. Moreover, a control system must offer an option of linking several LED screens into a network similar to an office network of PCs.
Here are some functions essential for a modern control system
Control system must channel video signal utilizing most functions of LED drivers;
Control system must have a modular structure to utilize different hardware functions;
Control system must be coordinated with scheduling software to offer the best options in scheduling clips on a LED screen;
Control system must have flexible adjustment of colors and brightness;
Control system must allow flexible adjustment of LED screen geometry since similar modules can be arranged in LED screens of different shapes and sizes.
An important option is to add individual screens to a larger LED screen network. To do this, the control system must support network interface for scheduling advertising clips and content and individual settings of screens.
Ideally, control system must be modular. In this case it’s possible to subdivide network functions and control of image generation. New option appears to build heterogeneous networks consisting of LED screens of different architecture, and even including LCD displays. The general control over the network will be exercised from a unified control center.
Currently, LED screen networks are controlled via the Internet. The network functions of control systems must include this option.
Monitoring of a LED screen
Control system must include functions of monitoring and feedback that includes:
Scheduler log that records what video clips were displayed on a LED screen;
Hardware log that records all defects and failures of the equipment. The more sophisticated the control system, the more detailed is this technical feedback;
Access log that records each entry into the system and each change in screen settings.
Information security of the LED screen control system
An LED screen is controlled by a PC. Any number of people may have access to a controlling PC. Therefore, the control system must have in-built information security functions.
This information security subsystem have the following safeguards:
Primarily, ways to prevent an unauthorized display of information on a LED screen;
Automatically generated logs must be protected from tempering;
Security subsystem must have options of running LED screen as part of the larger network and as an individual screen, too;
Integration with control system so that it could not be removed or deleted from the screen.
Electromagnetic compatibility (EMC) and electromagnetic interference (EMI) of LED screens
Large LED screen has many electronic components and is controlled via digitals system. This makes an LED screen similar to any electronic device when part of the consumed electrical power is emitted as electromagnetic radiation capable to induce electromagnetic interference (EMI).
This radiation results from high frequency switching of a very large number of components. Data and signals moving between PCBs generate radiation. An LED screen consists of many similar components – LED modules. The geometry of PCB layout multiplied dozens of times creates a gigantic antenna.
Electromagnetic interference (EMI) may interrupt, obstruct, or otherwise degrade the quality of radio and TV services or radio phones.
Minimizing the radio interference is the important task for developers of LED screens who understand in details all the intricacies of electronic design. This task may only be achieved by complex measures in developing electronic layouts, designing safe LED modules, controllers and wiring.