ADC 320F Network Card User Manual


 
Rate Adaptive Transmission
50 Megabit Modem 310F and 320F User Manual
You can configure the Megabit Modem 310F and 320F startup margin setting. This setting
defaults to 4 dB but may be set from 0 - 15 dB. The modems will attempt to come up at the
programmed margin setting. Setting the margin high allows for a cushion against changing line
conditions and impulse noise. Setting the margin low provides less protection but allows the
modems to come up at a higher data rate (if in rate-adaptive mode) or at a longer loop length (if
in fixed data rate mode). The default setting of 3 dB is recommended and provides an overall
BER better than 10
-10
. Reducing the setting to 0 dB will provide a BER of less than 10
-7
and
is not recommended.