RAD Data comm ASMi-52 - Manual (Page 75)

Installation and Operation Manual Chapter 4 Configuration
ASMi-52 Ver. 2.5 Configuring the Physical Ports 4-25
Configuring the Power Spectral Density
By configuring the power spectral density, you define the amount of power
applied to the spectrum of frequencies that carry the information signal in order to
achieve a satisfactory level of signal strength at the receiving end of the circuit.
The power spectral density can be configured for the ASMi-52 units with the line
probing set to fixed.
The power spectral density value depends on the selected modems’ compatibility:
Annex A or Annex B. The possible values are:
• Symmetric, supported in both Annex A and Annex B modes.
• Asymmetric, supported in Annex A at 768 kbps and in Annex B at 2048 kbps.
To configure the power spectral density:
1. From the SHDSL Local Port menu, select Asym PSD (Main menu >
Configuration > SHDSL Configuration > SHDSL Local Port > Asym PSD) to
choose the power spectral density value: symmetrical or asymmetrical.
The display is refreshed and a new value appears.
2. Select Save to save the changes.
• Remote ASMi-52 units automatically detect the line power density. This parameter
is permanently set to Sym/Asym Enable and cannot be changed.
Configuring Line Probing
By configuring this parameter, you force ASMi-52 to perform line probing in order
to find the best possible rate of transmission – adaptive rate. Or you command the
modem to skip the rate adaptation phase – fixed rate.
Only central ASMi-52 units with the 2-wire line interface support fixed and
adaptive rates, remote units operate with adaptive rate only.
ASMi-52 units with the 4-wire line interface support only fixed rate.
To configure line probing:
1. From the SHDSL Local Port menu, select Line Prob (Main menu >
Configuration > SHDSL Configuration > SHDSL Local Port > Line Prob).
The display is refreshed and a new value appears.
2. Select Save to save the changes.
Setting the Loop Attenuation Threshold
Loop attenuation is different (in dB) between the power transmitted from the
ASMi-52 modem and the power received by the unit operating at the other side of
the application. By setting the threshold, the modem is instructed to generate
minor alarm (LOOP ATTN. OVER LINE A/B) when the selected loop attenuation
threshold value is exceeded.
To set the loop attenuation threshold:
1. From the SHDSL Local Port/SHDSL Remote Port/SHDSL Repeater menu,
select Loop attenuation threshold (Main menu > Configuration > SHDSL
Note