HomePlug power-line communication

All about HomePlug power-line communication

What do the different LEDs on the HomePlug adapter mean?

EG4xxx and EG30xx meters can function with a wide variety of HomePlug AV compliant powerline communication adapters. Some officially supported adapters and their LED keys are shown below.

TRENDnet HomePlug AV (TPL-406E2K)

Typical Behavior
Other Behavior
POWER Indicates the adapter has power Green light No LED - no communication for too long or not receiving power
ETHERNET Indicates an Ethernet line connection On -  live Ethernet line connected
Blinking - sending/receiving Ethernet data
Off - may indicate an issue with network connectivity or a damaged Ethernet cable
DATA Indicates presence of powerline communication On - Powerline device connected
Blinking - sending/receiving powerline data 
Off - no connection to any HomePlug devices




Actiontec HomePlug AV (PWR500/PWR200)

HomePlug AV Adapter
LED Function Typical Behavior Other Behavior
PWR Indicates the adapter has power Green light No LED - no Ethernet communication for too long or not receiving power
LK Indicates a connection with the eGauge or another HomePlug AV adapter Blinking red light when communicating with the eGauge Blinking orange or green - possible connection with another HomePlug AV device
Off - no connection to any HomePlug AV devices
ETH Indicates an Ethernet line connection Blinking green light when transmitting data Off - may indicate an issue with network connectivity or a damaged Ethernet cable



HomePlug 1.0 HPE100T

HomePlug 1.0 Adapter
LED Function Typical Behavior  
Power Adapter has power and is connected to the eGauge or another HomePlug 1.0 device Green light when active, blinking green light when transmitting data Off - adapter is not receiving power, or cannot communicate to the eGauge
Link Indicates an Ethernet line connection Green when active, blinking green when transmitting data Off - issue with network connectivity or a damaged Ethernet cable

NOTE: Other HomePlug adapters from different manufacturers may work. However, since they have not been tested by eGauge we cannot guarantee full functionality. Troubleshooting and support may be limited in these situations. HomePlug 1.0 adapters are no longer available directly through eGauge - please see our article on locating replacement HomePlug 1.0 adapters for more information.

Can the HomePlug adapter be connected to a power strip?

HomePlug adapters should be connected directly into a wall outlet. If that is not an option, it is possible to plug the HomePlug into a power strip provided the power strip has no integrated surge suppressor. Most power strips designed for computers have integrated surge suppressors, so they are not suitable. Uninterruptible power supplies or power strips connected to uninterruptible power supplies are also not suitable.

Low-cost power strips are available at local hardware stores and generally work fine. Non-surge suppressed power strips may be referred to as "relocatable power taps". "Multi outlet taps" are also generally suitable. Extension cords may be used, but keep in mind that the length of the extension cord must be factored into the distance between the eGauge and HomePlug (40ft of wire run + 25ft of extension cord = 65ft between the eGauge and HomePlug).  Maximum effective communication distance is approximately 100ft.


HomePlug Security Considerations


Some eGauge models have integrated powerline communication, commonly known as "HomePlug communication" or just "HomePlug". These eGauge models inject a signal into the conductor connected to the L1 terminal of the eGauge and attempt to communicate with other powerline communication devices that are within range connected to the same power line using the HomePlug standard. This effectively acts as a powerline-Ethernet bridge when used to connect an eGauge to a network with a HomePlug adapter.

eGauge2 model units utilize the "HomePlug 1.0" protocol, while newer model eGauges (EG31xx, EG41xx) utilize the newer "HomePlug AV" protocol. "HomePlug AV" is not backwards compatible with "HomePlug 1.0", and the devices will not see each other or communicate. The HomePlug 1.0 standard is no longer in common use, and HomePlug 1.0 adapters may not be readily available.

The HomePlug signal’s reach is limited to about 100ft of wiring and does not extend beyond transformers or cross phases. Thus, for most single-family homes, the HomePlug signal will be contained to within the home itself. This is in contrast to a WiFi signal, for example, which usually can be picked up easily outside a home.

Security Considerations

All HomePlug devices have a "password" or "encryption key" assigned to them. Any HomePlug devices with the same encryption key can communicate to each-other and form a "HomePlug network". By default, the HomePlug 1.0 encryption key is "HomePlug" (case sensitive, without quotes) while the HomePlug AV default encryption key is "HomePlugAV" (case sensitive, without quotes).

Because the HomePlug devices come with default encryption keys, buildings that share electrical services (e.g., possibly duplexes, apartment buildings) may have the HomePlug signal extended into neighboring units which could then allow an individual to obtain someone else's network access via a HomePlug adapter if both are using the default encryption keys. Therefore, it is important to set a unique encryption key on any HomePlug networks that may share a power line with another unit.

HomePlug AV (models EG31xx, EG41xx) utilize the HomePlug Green PHY specification and are compatible with HomePlug AV using 128-bit AES encryption.

HomePlug 1.0 (model eGauge2) utilize a HomePlug 1.0-compatible link and are encrypted with 56-bit Data Encryption Standard (DES).

It is best practice to utilize a unique and secure HomePlug encryption password, but in many private residences it is unlikely to be an issue because of the limitations of powerline communication (specifically, it is unlikely the HomePlug signal will propagate beyond the building's electrical wiring).

More information can be found on the HomePlug Alliance website at http://www.homeplug.org/.

Related Articles

Pairing an eGauge with a HomePlug adapter

What do the different LEDs on the HomePlug adapter mean?

What are some common causes of HomePlug communication issues?

How do I pair the eGauge with a HomePlug adapter?


By default all HomePlug-compliant PLC devices use the same encryption key - this means that, out of the box, any HomePlug-compliant device should be able to connect to any other HomePlug-compliant device without any adjustments. However, if there are multiple HomePlug adapters in the same location, or if there are security concerns regarding PLC traffic, it may be necessary to pair an eGauge with its HomePlug adapter. This is typically not required for most installations.

This article has instructions for pairing eGauge devices with their respective HomePlug adapters. Also included are instructions to rescue an "orphaned" device (that is, an eGauge or HomePlug with an unknown encryption key). These steps typically cannot be performed remotely, and require physical access to both the eGauge meter and the HomePlug.

In new installations, pairing is optional but not required. The eGauge and HomePlug adapter should communicate out of the box. If they do not communicate, there is likely a distance or installation issue; pairing will not correct these issues.


HomePlug Basics

    What is HomePlug and how is it used?

    Technical And Environmental Considerations

    How Secure is HomePlug Communication?

Changing the HomePlug Encryption Key (pairing)

     Push Button Method (EG301x meters)

     LCD Method (EG41xx meters)

     HomePlug Adapter Push Button Timing

Push Button Pairing Process

Pairing through the eGauge user interface

Recovering an Orphaned Device

     Via eGauge UI

     Via Vendor Software

HomePlug Basics


What is HomePlug and how is it used?

HomePlug is a Power Line Communications (PLC) specification used to transmit networking data over standard power lines. Thus, all HomePlug devices are PLC devices, but not all PLC devices use HomePlug. It is commonly used to create a network bridge  in a location where Wi-Fi can not work or is not convenient. Think of the HomePlug adapter as a "translator" that can convert an Ethernet signal into a form which can be sent over existing power lines, and vice versa. HomePlug adapters may commonly be referred to as "HomePlugs", although this can be confusing.

HomePlug adapters are commonly mistaken for wireless (WiFi) devices. Standard HomePlug adapters have no wireless component. A physical connection to an outlet and a router (via Ethernet) is required.

Typically, one HomePlug adapter is connected to a router with Internet access, and another is placed elsewhere in the building so Ethernet-capable network devices may connect to it. eGauge meters have a built-in HomePlug adapter, so only one HomePlug adapter is required when using an eGauge. Examples of common HomePlug adapters are shown below: