Configuration Option Tables
A-9
7970-A2-GB20-00
August 1999
Table A-3.
Synchronous Data Port Options – Models 7975 and 7985 (3 of 3)
Port (DTE) Initiated Loopbacks
Possible Settings: Disable, DTLB, DCLB, Both
Default Setting: Disable
Allows the initiation and termination of a local Data Terminal Loopback (DTLB) or
remote Data Channel Loopback (DCLB) by the DTE connected to this port. (DTLB is
equivalent to a V.54 loop 3, and DCLB is equivalent to a V.54 loop 2.) Control of these
loopbacks is through the DTE interchange circuits as specified by the V.54 standard.
Disable – Disables control of local DTLBs and remote DCLBs by the DTE connected to
this port.
DTLB – Gives control of the local DTLBs for this port to the DTE attached to this port.
This loopback is controlled by the Local Loopback interchange circuit LL (CCITT 141).
DCLB – Gives control of the remote DCLBs for the far-end port connected to this port to
the DTE attached to this port. This loopback is controlled by the Remote Loopback
interchange circuit RL (CCITT 140). The far-end equipment must support in-band
V.54 loopbacks.
Both – Gives control of local DTLBs and remote DCLBs to the DTE connected to this
port.
ElasticStore
Possible Settings: Disable, Enable
Default Setting: Enable
Used to enable or disable a first-in, first-out (FIFO) buffer circuit for the incoming
external clock. This circuit is used to compensate for the differences between the
frequencies of the data clocks for the two units in the circuit. This option only applies if
the unit is set for external timing. Do not enable Elastic Store if the attached DCE has
an elastic store buffer larger than 32 bits.
Disable – Disables the Elastic Store FIFO.
Enable – Enables the Elastic Store FIFO.
Summary of Contents for Hotwire 7974
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