Display Size - The height of the display characters determines the distance that the LED sign can be read. See Chapter 6 for a chart showing the min / max viewing distances for various LED sign character heights.
Display size also drives the cost of an LED sign. Prices for various single line displays are approximately . . .
Multi-line displays can run $2000 and up.
Single Color vs Multi Color - Single color LED signs can display one color, usually red, green or yellow. Multi color LED signs can display multiple colors, usually red, green and yellow, with blue and white now appearing. In some applications, a single color LED sign is preferred since they are easier on the recipient to read, easier for the sign owner to enter text, easier to program, and usually use less energy.
The most effective color for LED signs is red on the sign's black background. Our eyes are naturally drawn to the color red, as it is a warning and emergency color. Yellow, white, blue and green are not, and are not seen as readily. If you want more people to read your messages, make it all red.
Multi color LED signs can display text in single colors, or in a combination of the colors, creating what's referred to as rainbow colored text.
Multi color LED signs provide flexibility on what color you use and when to use it. They also allow to you convey added information via color, for example, red for down arrows, green for up arrows. Or for example, green for summary data, and red for alerts.
When you have a captive audience, such as in a waiting room, cafeteria, or lobby, red can be overbearing, and the use of green or yellow will be better received. When you have an audience in motion, such as on a street, in a car, moving red text is the best, as it will catch more eyes.
Brightness - After size and color, the next most important aspect is how bright the LED's are. For indoor applications such as offices, lobbies and retail outlets, you want an LED sign that is designed for indoor lighting conditions, and which are less bright.
When you are planning on having an LED sign indoors, but facing outdoors, through a window or open area, you will need a much brighter LED sign. The bright daylight will wash out the light from LED signs designed to be used indoors. Bright LED signs that can be read in outdoor lighting conditions are referred to as Super Bright LED signs.
Weatherproofing - While an LED sign may be bright enough for outside visibility, most LED signs cases are not weatherproof. If you will be placing your LED sign outdoors, you will usually need to contract with a local sign maker to construct a weather proof enclosure for your LED sign, if the sign is not weatherproof.
A lower cost option is to place an outdoor visible LED sign behind a window so that it faces outside, thus avoiding the cost of a weatherproof enclosure, or weatherproof sign.
Programming Effort - To display right to left scrolling text for most LED signs is as simple as typing in the text on the keypad and clicking a Start / Run button. If you want to change colors, change scrolling directions, or use special effects to display the text, you will need to start entering codes to do this. This entering of codes is called programming by most LED sign manufactures. A simple text message with a few codes might look like this . . .
With most LED sign uses, the information to be conveyed is straightforward, so there is no need for complicated sweeps, transitions, multiple fonts, colors, background, etc. Some of the animation options in signs go too far and become a programming burden for the LED sign user, and a distraction to the message reader if not used properly. In addition the fancy transitions waste the reader's valuable time, which may just be a second or two.
An LED sign with commands for scrolling text right, left, up, down, a few opens, closes, clocks, erases, upper/lower case characters and a few user programmable graphics, is sufficient for 80% of LED applications. Purchasing an LED sign with more features will add to the cost and programming burden as you try to use the more complicated functions. If your needs are simple, stick to a simple sign.
Additional Fonts - Unless you have a unique application you will not need additional fonts. Most LED signs use a 5 x 7 dot matrix to display the characters, and with so few dots, there is not much different between fonts at that resolution. You can usually get large characters by making them double wide. The exception to this is when your application requires a foreign language font. Most displays can already display many of the European special characters, and most displays let you define your own special characters, which can be characters or graphic symbols.
Dot Matrix - Lower cost LED signs use a 6 x 7 dot matrix to represent a character. The character usually takes up a 5 x 7 area of the matrix, with the 6th column for the gap between characters. More expensive LED signs may use a larger matrix, such as 12 x 14. The more dots that are used to represent a character, the sharper the character will appear, and the more expensive the LED signs will be, since the number of LED's will increase by 4 times, or more. If the objective is to have text that moves, then the benefit of a denser dot matrix is reduced, since our eyes naturally smooth out the edges of characters that are moving. Larger dot matrix 12 x 14 LED signs are better in applications where the reading audience is close to the sign, in the 5 to 15 foot range.
Memory Space - Most LED signs come with sufficient memory space to handle 90% of the LED sign applications. Most signs come with memory from 4,000 to 30,000 characters. Make sure the LED sign you are considering has sufficient memory for your messages. For example if you have 20 different message sequences of say 125 characters each, you'll need memory space for 2500 characters (20 messages x 125 characters). Remember to allow for scrolling commands and color changes, as these functions take up memory space too, likely reducing the available character space by 20%.
Viewing Distances - Since LED signs scroll text that is made up of a coarse matrix of dots (5x7), it can be hard to read the LED sign when close to it. This is one reason why there is a minimum distance recommended for various sign character heights. The character height determines the viewing distance. See Chapter 6 for a table of various min / max viewing distances for different LED sign character heights.
Ease of Use - Since LED Signs are electronic, you can change the message. Most LED signs come with a TV like remote control device that allows you to change the message from a distance. Many also allow you to change the message via a computer keyboard, or via a computer program and a cable.
The computer method will require you to have your computer near the sign, or your sign must be attached to a network, for you to change the message. With a remote keypad, you can change the message without need of a computer.
By being comfortable and knowing the ease at which you can change a message, it is more likely that your messages will be kept up to date. Expiring messages might include a sale that has ended, a product that is out of stock, or a price has changed.
Life Expectancy - LED Signs have no moving parts so you should expect a quality sign to last a long time, 10 years or longer. If designed and manufactured properly, most electronic equipment, such as LED Signs, will last 10 years or longer. If a quality sign is going to fail, they will usually fail within the first 30 days of use. Be sure the sign you buy comes with a minimum 30-day guarantee, and use it as soon as it arrives. Also make sure the company that makes your sign has been making them for many years. Manufacturers of poor quality signs do not stay in business long.
If you are planning on using your LED Sign outside, make sure your sign is designed and rated for outdoor use.
Controlling Multiple Signs - The best way to control multiple LED signs is via a PC with software designed to do this. Each LED sign you use will require a way to get the message from the PC to the LED sign. Usually this is over a serial data cable and a serial port on the PC and the LED sign. Newer PC's only have USB ports so you may need to buy a USB to serial adapter, for $20 or so. Newer LED signs have USB and or Ethernet ports built into them.
To control multiple LED signs you need to look at the controlling software to make sure it was designed to control multiple LED signs. Some software packages let you send multiple messages to multiple signs with one click of the mouse. Also make sure the software lets you save the messages for all your signs in a file on the PC for later use and for backup purposes.
Ethernet Control - One of the newer methods to control LED signs is via an Ethernet network connection. This means the LED sign mush have built in an Ethernet interface. You can add Ethernet capability to most LED signs with the addition of an Ethernet-to-Serial adapter. This device, which usually sells for $90 to $150, will convert the Ethernet protocol, to the serial or USB protocol, that an existing LED sign uses.
The advantage of an Ethernet network connection is that the LED sign literally can be halfway around the world, and yet controlled at your PC's desktop, providing your PC and the LED sign are both connected to the Internet, or LAN.
A network connected LED sign can be controlled by any PC that is connected to the same network. If the LED sign is given a public IP address, the LED sign can be placed halfway around the world, and controlled via a PC connected to the Internet.
Click for . . . Chapter 3 - LED Sign Regulation Issues & Options