ZyXEL PLA-402 v3 User Guide - Page 54

Chapter 6 The OS X Configuration Utility Table 11 Link Information (continued) LABEL DESCRIPTION Avg. Bits/Carrier This field displays the average number of bits transferred over the connection measured in Mbps. This represents the physical rate of data transmission (the PHY rate) which includes not only the files sent on your powerline, but also line overhead required to manage your network, such as error correction bits. The PHY rate is the clearest indicator of the quality of your line. Avg. SNR/Carrier • If the PHY rate is close to the HomePlug AV maximum data transfer rate, then the quality of this section of the line is very high, with very little attenuation. • If the PHY rate varies between the maximum level and a lower level (such as 60 Mbps), there is noise on this section of your powerline. Attenuation is not a factor. • If the PHY rate is steady at a lower level (such as 80 Mbps), this is caused by attenuation and not noise on this section of your powerline. This field displays the average Signal to Noise Ratio (SNR) measured in dB. Use this to check the amount of noise on this part of your powerline network. The higher the number the better the connection quality. Avg. Attentuation/ Carrier Noise on your powerline coaxial network is usually caused by household appliances running on your powerline coaxial network. The motor of a refrigerator can create electrical interference. A cell/mobile phone recharger which rapidly alternates between on and off can also generate noise. Poor cable quality and installation can also cause noise. To identify causes of noise on your network, disconnect an appliance connected on this part of your powerline coaxial network and observe whether this reduces the Signal-to-Noise ratio. This field displays the average attenuation measured in dB. Attenuation is the reduction in strength of a signal as it travels over a transmission line. Use this field to check the reduction in the strength of the signal between two devices. Attenuation may vary considerably across a powerline coaxial network as line conditions also vary. A typical level of attenuation may be 40 dB, but may reach over 70 dB, depending on line quality and distance. Avg. Output Power/ Carrier Clear Statistics Close A main cause of attenuation is the power requirements of appliances on your electrical circuit. Powerline traffic near an appliance such as a refrigerator may be affected by attenuation more than on other sections of your powerline coaxial network. This field shows the average power produced by the source device. Power levels should be constant and limited by the output power standard of your country. Unusually high output power levels may damage your device. Click this button to reset all counters in this screen to zero. Click this button to close this window. 54 PLA-402 v3 User's Guide