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Adaptive Display's Digital Signage Blog

Choosing the Best Communication Method for LED Signs

Posted by Lexi Stevens on Tue, Jul 07, 2015

LED signage is an important communication means for businesses and organizations. As a digital sign owner, it is essential that you know how to communicate or deliver content to the display.  

There are several ways to communicate with your digital display. One important factor you need to understand is that the requirements of the display depend on your specific installation type. This will help you choose the right technology for your application. Electronic message center manufacturers may provide some or all of these communication methods with their displays.  

These communication methods can be: Hard Wired or wireless   

Hard Wired Communication Methods  LED Sign Communication Methods

LED signs were typically hardwired in the past using phone modems or serial cables. Previously, this method was used since signs were not as sophisticated and there was less data sent to the sign. As technology advanced, signs required larger file sizes. The phone and serial cable means of communication were replaced by Ethernet network cable or Fiber Optics. Ethernet and Fiber Optics have become the standard wired method, while the older options are used in special situations like factory production floors.  

1. Ethernet TCP/IP

 TCP/IP over Ethernet network is the most common communication method.   

This method makes use of the Ethernet communication card installed in your computer and used to communicate with the LED display. Most LED sign manufacturers offer this type of connectivity without special adapters. It is usually used for wall mounted signs and street signs that are closer to the building or network drop. Ethernet TCP/IP is more durable than Fiber Optics.  
Recommended use:   

Ethernet cable should not be more than 300 ft in length. If the distance is more than 300 feet, extend it by connecting to an Ethernet HUB or Switch.    

2. Fiber Optic Cable

Fiber Optics is a communication method that uses fiber optic cables that utilize light to send information from your computer to the LED sign.  

Fiber Optics can go farther distances and have a lower transmission delay. However, this is risky and expensive to run and repair. Military signages usually use this communication method.  

Recommended use:

  • Distances up to 40 miles with single-mode and 10 miles using multi-mode.
  • High speed communication for sending large files quickly
  • When you need access to the sign from a company wide network
  • When you need medium cost and high speed communication method
3. Phone Modem

Phone Modem is a communication method that uses a phone line to communicate with the sign.  

Communication speed is controlled by the modem and depends on the integrity of the phone lines. The phone company usually charges a fee for this access. Contact the local phone company to check if they have phone lines near the sign. Your computer also requires an external phone modem to have access to the LED sign.  

4. Serial Cables

RS232: RS232 is a two-wire communication method. This is a simple connection system that is easy to use and install. It is used when only one LED display is connected to the computer.  
Recommended use:
  • When the distance between the computer and LED display is less than 50 feet (15m)
  • When communicating with the sign using a laptop.
  • When sending messages, not large files

RS485: RS485 is also a two-wire communication method. This can connect several LED signs to one computer. This connection is simple, easy to use and install. It requires the use of a converter since most computers do not have this port.  

Recommended use:

  • When the distance between the sign and computer is less than 5000 feet (1500m) but greater than 50 feet.
  • When sending messages only
  • When connecting several displays using only one computer

Wireless Communication Methods  

Wireless communication is best used for LED displays that are within 100-200 yards from the transmission point. The line of site should be clear with no walls or buildings between the radios.  

This method has a low infrastructure cost to implement. Wireless communication methods for LED signage vary in price, reliability and capability.   

Common Frequency Types:

  • 900 Mhz: Longer distance but slower data rate
  • 2.4 Ghz: Standard WiFi frequency
  • 5 Ghz: Higher data rate and more secure

 1. Radio Frequency

Radio Frequency used modems that that operate in a 900MHz range. It consists of a transmitter attached to the computer and a receiver that resides in the sign. This method is recommended for outdoor applications. Most manufacturers prefer this method since it allows a broad range of installation types and does not require a conduit to be installed in the ground.  
Recommended use:

  • There should be a clear line of sight between the transmitting computer and the LED sign.
  • Supports transmission distance of up to 2 miles.
  2. Wireless Ethernet

Wireless Ethernet is sometimes called WiFi or a bridge. This method usually has a data encryption or key to access the network and prevent unauthorized access.  

In using this method, a site survey is needed to ensure that the Wireless Ethernet will work properly. There should be no excessive interference from the sign to the transmitter location.  
Recommended use:

  • When you need high speed connection to send large movie or picture files to the sign.
  • Signage can be accessed from several computers or from a company wide network.
3. Cellular Modem

The cellular Modem method is gaining popularity but it is still not being used frequently. This allows access to the sign over the same data network as your smart phone (3g, 4g, LTE, etc.). It can be set up anywhere as long as cellular signal is strong and available.  

When using this method, a "Data Only" monthly plan through a wireless carrier is required. The wireless carrier will then provide an external internet IP address that the Cell Modem (ATT, Verizon, T-Mobile, Sprint) will use. This Cell Modem is connected to the sign using a secured router.  Messages to the sign are sent using the unique IP address.  
Recommended use:

  • For signs in controlled off-site and remote locations.
  • For a cloud-based content management system.

In Conclusion  

Communication to your sign is important. Understand the pros and cons of using each method before making a decision. Consult with your trusted sign dealer or manufacturer to ensure that you receive the best possible solution and equipment. 

For Advice on Communication Methods, Contact Us Here!

Tags: led signs, LED Digital Display, LED Software, Communication Methods, Digital Signage, Communication, Digital Displays