- Scott Hofheins
LED sign technology is still new to many IT professionals who deal mostly with networks, servers, user computers and well documented software. It’s not that LED sign technology is overly advanced or complicated, but that it’s just not something they have to deal with every day. Additionally, the industry is growing and changing so quickly that it’s difficult to find any substantial “standards”. Blogs like ours are helping to improve this, but the industry as a whole is still blanketed with confusion and misinformation.
I would like to offer a basic FAQ for IT folks who often get pulled into an LED sign project and counted on to make an “expert” decision on one product or another. I've included as many links to related blog topics as I could find. Don't’ worry I promise they are not those annoying advertising links.
What are the basic components in an LED Sign?
There are some common components that every LED sign must have. Manufacturers use a variety of names for their hardware, so the names I’ve listed the names below according to their function.
- Controller: The brain of an LED sign. This holds the files and raw data that will be shown on the LED sign. In the past, this was a simple embedded controller that sent text and simple animations to the display. Most manufactures are now using IPC Controllers running an actual OS. These are industrialized PC’s that are more powerful, easier to control, and easier for IT staff to manage.
- Video Conversion Hardware: The video information supplied by the Controller has to be converted to a signal that LED system will understand. In most cases this is a separate piece of embedded hardware, with a video connection to the computer on one side, and a output connection to the rest of the LED sign hardware on the other.
- Video Sectioning Hardware: This hardware splits the video signal and sends it to a specified section of an LED display; typically Rows or Columns of data. This allows manufactures to create larger signs by adding more of these “sectioning” cards for additional rows or columns of an LED display.
- LED Modules and Drivers that hold the actual LED’s: These are the actual LED’s that light up and display the information on the LED sign. They are usually grouped into “Modules” containing multiple Pixels. Usually 8x8 pixels, 8x16 pixels, or 16x16 pixels. Each pixel on a color sign will contain at least (1) Red LED, (1) Green LED and (1) Blue LED. These LED’s are driven by the IC chips, typically incorporated with the module itself.
- Communication System and Hardware: The end user must be able to communicate with the LED sign. In the past, embedded controllers were built to natively support Serial communications (RS232 or RS485). However as the need for more data increased, and networks were modernized, manufacturers responded with IPC based controllers that supported direct TCP/IP communication via standard RJ45/Cat5/6 cable. This is now the standard. Other communication options are easily implemented using Wireless Radios, Fiber to Ethernet Converters, etc…
- Sign Software: In the beginning, these were command line programs. As the industry grew, manufacturers developed better GUI’s and more powerful software to control full color signs with animated media, text and video. For a long time these were just local PC based installations, but we are now seeing Cloud Based options too.
How does this all work together?
- The user will create a message for the display, and add it to a schedule in the sign software.
- The software (cloud based or local) will then communicate to the controller and update the schedule and files.
- The controller then plays these files according to the schedule sending the video signal to the Video Conversion Hardware.
- This converts the signal and sends it to the Video Sectioning Hardware.
- The video is then sent to each LED module in the particular Row or Column where the IC chips tell the individual LED pixels how to balance their colors to create match the corresponding pixel in the video.
- Put all those pixels together, and you've got yourself a full color image on the LED sign.
What risk factors are involved for network security?
An LED sign with an IPC controller will have some inherent protections due to the fact that’s its sole purpose is to take content from the sign software and display it on the sign. That’s it. Nobody is surfing the internet with it, or sending emails, clicking on questionable links, or running questionable software. It’s a self contained system, with limited access over a network. The controller and communication devices for the sign should be encrypted and password protected by the factory. End-users can enhance this security by customizing these protections. This is done much easier on an IPC controller because it’s using a standard OS.
What are considerations to take when looking at LED sign software?
- Local Software: This has been around for awhile. You install it just like any software program, then set the corresponding settings to communicate to the LED sign. Local software offers more physical control of the software on-site, but it usually limited in remote functionality and users. It should be well documented, simple, and developed by the manufacturer directly, preferably in the US. Avoid software that looks outdated or poorly designed. Most major manufacturers can demo the software, or provide good documentation with screenshots.
- Cloud Based: This approach to sign management allows the sign to be controlled through a secure website. Because it’s internet based, users have the ability to access it 24/7. You have more control and options for users and permission based roles. Local access to the sign is restricted, allowing IT staff to control user access through the web portal. This type of system takes a bit more setup on the front end to get the sign onto your network and online, but is typically worth the effort.
What makes a quality LED sign?
As with any electronic device, it’s all about the quality of the engineering and execution of manufacturing with high quality components. The entire system should be designed and engineered in house. There are many so called “manufactures” out there who outsource the entire build overseas, shipped pre-built to the USA. These organizations have a severely diminished ability to implement QC and support the product long term.
Are there common “red flags” to look out for?
Signs manufactured wholly in Asia.
No documentation available for the sign.
Poorly translated documentation.
Difficult to reach a real person at the “Factory”.
Manufacturers not willing to provide a physical address, or who only provide a PO box.
Extremely low pricing for “the same” product when compared to other quotes.
Extremely high specification numbers that seem too good to be true.
What is a Pixel Matrix, Pixel Pitch and RGB?
Pixel Matrix is the physical pixel size of an LED sign, usually shown as Height x Width. Pixel Pitch is the physical distance between each pixel, measured in Millimeters (MM). RGB stands for “Red” “Green” and “Blue” and is a designation that the sign is full color. For example, a 20mm RGB 48x128 LED sign would be:
- 20 Millimeter Pitch
- Full Color
- 48 pixel high, by 128 pixel wide Matrix
Some manufactures offer Virtual Pixel Technology. When done correctly, this will enhance your sign, and allow you to use double the native Pixel Matrix in the content you program on the sign. For example, if your LED is 48x128, you would be able to use content that is sized to 96x256.
How do you measure the brightness and color palette of an LED sign?
Both of these specs are important, but have been very abused and over-inflated in the past and causing a lot of confusion for end-users. Keep this in mind when comparing specs.
The most brightness specs are listed as NITS. These are measurement of light directly from the source. You want an LED sign to be around 10,000 NITS. Extremely high NIT specs are typically an over inflation of the actual spec, or the LED’s are being driven harder with more voltage, causing premature failure over time.
The color palette is measured like your computer monitor according to bit depth. Realistically speaking, anything between 16.8 million, and 281 Trillion is standard in the industry. Larger values are over inflated and don’t make any difference on the actual color quality of the LED sign. A typical monitor supports 16bit (65 Thousand Colors) and 24bit (16.8 Million Colors). 32 Bit is still 16.8 Million, but with 8 extra bits that give transparency values. However, 48bit does provides 281 Trillion colors.
Is a larger manufacturer always better?
No. Large manufacturers have to deal with many of the same issues as smaller manufacturers, but can be much slower to respond. Organizations like Wal-Mart are huge, but you’re not really getting the highest quality products. When you're purchasing an LED sign for $50k, you do not want a “Value Brand”. The size of the manufacture is a factor, and you want to make sure they are well backed, financially healthy and underwritten, but it’s not an automatic benefit.
I know I haven’t covered everything, but I hope the links I provided helped to expand the range of information. If you didn’t click on them, I highly recommend going back when you get time and read those posts. We have a great team here that strives to produce true and honest information about LED signage for both end-user and dealer alike. We are currently at 130+ posts and look forward to even more as the year moves on. So keep us bookmarked, and feel free to comment with any questions, ideas for topics, etc…we’re listening.
I hope this post has been informative and helpful. As usual, I welcome ALL constructive comments. Please feel free to comment and add anything I’ve missed, or additional tips you may have regarding this topic. Please visit www.vantageled.com for many other resources, white papers, and of course: Great looking LED Signs!
**All posts/thoughts/writings are strictly the viewpoint of me and me alone and do not reflect nor speak for Vantage LED’s beliefs, attitudes, thoughts, etc. unless specifically stated.