bLine Coding: HDB3 (default)
Options: AMI, HDB3
HDB3: In this line coding, the transmitter substitutes a deliberate bipolar violation when excessive zeros in the data stream are detected. The receiver recognizes these special violations and decodes them as zeros. This method enables the network to meet minimum pulse density requirements. Unless AMI is required in your application, HDB3 should be used whenever possible.
AMI: Alternate Mark Inversion defines a pulse as a "mark,” a binary one, as opposed to a zero. In a E1 network connection, signals are transmitted as a sequence of ones and zeros. Ones are sent as pulses, and zeros are sent as spaces, i.e., no pulse. Every other pulse is inverted from the previous pulse in polarity, so that the signal can be effectively transmit- ted. This means, however, that a long sequence of zeros in the data stream will cause problems, since the NTU receiving the signal relies on the signal to recover the 2.048 Mb/s clock. If you must use AMI, you should ensure that the data terminal equipment connected to the unit provides a minimally accept- able pulse density. For this reason, there are advantages to using HDB3 instead.
dClocking: Network (default)
Options: Network, Internal, External
Network: This is the most commonly used setting when connect- ing to a carrier’s network. In this mode, the unit recovers the clock from the received signal and uses it to transmit data. In this way the unit remains synchronized to a master clock. In campus applications, one of the units must be set to Internal clock, and the other end is set to Network clock. At all times, there must be only one clock source. Otherwise, clock slips and framing errors and bit errors may occur.
Internal: This is commonly used in campus applications, where the unit is not connected to the public telephone network directly. In this mode, the unit uses the
External: In this mode, the unit requires a clock signal from the DTE via the external clock pin on the DTE interface connec- tor. Most applications will use Network or Internal clock modes.
eLine Build Out: 120 Ohm (default)
Options: 120 Ohm, 75 Ohm
120 Ohm: Use with 120 Ohm
75 Ohm: Use with the 1001RCM11575 rear card. (Dual BNC connectors)
f
Options: Enabled, Disabled
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