In this article, we describe the technology of Powerline (PLA) and show you can troubleshoot connection problems on PLA
Powerline technology has made significant progress in recent years, becoming more powerful and more susceptible to failure with each generation. The electrical installation used for data transmission was originally not designed for this application, so some points need to be given special consideration. It is therefore advantageous if some technical background is known for planning and commissioning.
- PLA-400 series, 200 Mbps, from 2007
- PLA4205 series, 500 Mbps, from 2012
- PLA5205 series, 600 Mbps, from 2013
- PLA5206 series, 1000 Mbps, from 2015
- PLA5456 series, 2000 Mbps, from 2016
Although the data is transmitted over the power network and thus over copper cables, the connection is not comparable to a network cable over the same distance. The information is modulated via a high-frequency carrier signal in addition to the mains voltage. The gross data rate depends on the signal quality that can be achieved on the power grid. Distance to be bridged, phase used, and possible sources of interference influence the actual achievable data rate. The gross data rate also contains much information about transmission control and error correction, so that the measurable net data rate is much lower.
Inter-phase data connection
Normally, in an apartment, a single-family home, or an office floor, the electrical load is distributed over three phases. So it may be that powerline adapters have to communicate at different sockets over different phases (L1, L2, L3). The Powerline-technology uses the crosstalk of high-frequency signals to transmit data across phases. To do this, however, the power lines must run parallel over at least a short distance. Unfavorable conditions can lead to reduced speed or even connection interruptions.
If the transmission works perfectly on the same floor, but not eg from the cellar to the first floor, the cause is most probably the use of two unequal phases. The electrician can improve transmission through the use of phase couplers. The phase coupler establishes an electrical connection for high-frequency signals between the different phases.
Data connection via electricity meter
Often, apartments and cellar compartments respectively shared parts of the house are led by independent electricity meters. Depending on the age of the electrical installation and design of the meter, the powerline signal can be more or less damped. If the damping makes the reasonable use of Powerline impossible, the transmission of the useful signal from the electrician can be improved by signal couplers. The signal coupler establishes the connection of high-frequency signals via strongly attenuating electrical components such as electricity meters, fuse elements, or filters.
Influences of electrical consumers
Many consumers with an electric motor (vacuum cleaner, heater with blower, washing machine), switched-mode power supplies (mobile phone, notebook, PC), or power control (lamp with dimmer) cause high-frequency interference. If these disturbances reach the power grid, they affect the powerline signal transmission.
Tips for error limitation
Powerline adapters older than the PLA-400 models use a different powerline technology. Although they can be used simultaneously on the same power grid without disturbing newer adapters, they are not compatible with them.
The PLA-400, PLA4205, and higher are compatible and can be mixed. The speed is limited to the data rate of the slowest adapter. Practice shows that even mixed connections gain stability through the current models.
- Network password
Each powerline adapter communicates only with compatible adapters with the same network password. Depending on the adapter and documentation, the network password is sometimes referred to as a network name or Network Membership Name (NMK). The following network passwords are predefined in the factory settings:
- PL-100 Series: HomePlug (not compatible with current adapters)
- PLA-400, PLA42x5 and PLA52x5 series: HomePlugAV
For high security against eavesdropping, all Powerline devices that are allowed to communicate with each other are configured with the same password. All other Powerline devices are denied access. To avoid the risk of exposing your data to the neighbors, it is advisable to set an individual network password just as with wireless networks.
All adapters of current generations provide a key to automatically exchange a key. For the distribution, it is best to connect the adapters to a common socket and start the key exchange with the key. The Quickstart Guide provides information about the signaling via LED. Software is often no longer included with these models.
- Exclude interference from other consumers
With poor signal strength or insufficient bandwidth, it should be clarified whether another consumer is bothering. To do this, disconnect all power consumers from the mains (unplug the power plug!). The sole switching off of the consumers is often not enough since often the fault-causing power supply remains connected to the mains. If the cause of the fault is known, it may already be sufficient to operate this or the powerline adapter at another socket. An additional improvement brings the use of high-quality network filters before the disturbance-causing consumers.
Improvement of the bandwidth
Even though the connection is basically stable, by following the general tips, you can improve the available bandwidth. Often, this is enough for the repositioning of some consumers and the powerline adapter. Likewise, the direct connection of the powerline adapter and the routing of as many consumers as possible via a mains filter have proven their worth.