Chapter 1 General Information
MX-2100/2104
Installation and Operation Manual
1-44 Application Considerations
A operates in the loopback timing mode to ensure synchronization. The clock for
KML B can be any relevant internal or external source.
When a main link operates in DTE timing mode with the other main link as the
clock source, the receiving main link timing must be locked to the source main link
clock by the DEF SYS command (defined by the LINK_CLK parameter).
MX-2100
MX-2100
Any Timing
DCE Timing
Loopback Timing
I/O M
o
d
ule
s
KML A
KML B
XMIT
Clock
RCV
Clock
Figure 1-33. Typical DCE from ML Timing Mode Application (KML.7, KML.8, KML.F)
Main Link Timing Considerations in Bypassing and Multidrop
Configurations
In bypassing and multidrop configurations, data is directly transferred between the
two links of a MX-2100-2100 unit. To maintain bit integrity, the two links must
have a common timing reference. All the MX-2100 units connected in a system
that uses bypassing and multidropping must use a common timing reference.
The KDI module can be used to determine the reference source for both main
links of a MX-2100, by internally locking their timing. The available selections are
as follows:
•
Link A
: the clock of main link A serves as the local reference, therefore the
timing of link B is locked internally to link A timing.
•
Link B
: the clock of main link B serves as the local reference, therefore the
timing of link A is locked internally to link B timing.
•
None
: each link interface receives external timing signals from a common
reference source.
When two links in a system configuration are connected to different channels of a
data network, neither link can be selected as a timing reference for the other link.
The channels have their own timing reference. The connections are usually made
by modems or other data communication equipment that provides receive and
transmit timing signals, and the two links use DTE timing. In this common situation,
the common timing reference requirement is inherently fulfilled (the timing
reference is provided by the data transmission network).
Note
