Off-Net Extension Applications - Multitech MT56DSU2 Owner's Manual

MT56DSU2 Owner's Manual
The MultiDSU56K uses 4-wire non-loaded metallic circuits for LADS applications. The table below
outlines approximations for the maximum cable length for limited distance applications.
Data Rate
2400 bps
4800bps
9600 bps
19200bps
56000 bps
Note that line characteristics will vary depending on cable type/manufacturer, splices, bridge taps, etc.
An example of a typical LADS application is shown in Appendix A of this manual.

3.4.2 Off-Net Extension Applications

The MultiDSU56K can be used as an off-net extension with standard analog modems and lines to complete
DDS circuits in areas where the DDS is not available or where a customer requirement is for an extension
of the circuit for a special application.
In applications using the MuI1iDSU56K for an off-net extension, one Mu1tiDSU56K may be set for
External Timing and the other set for DDS Timing; however, in this application, the clock (timing) being
supplied must be accurate to +/- 0.008% of the enabled data transmission rate.
The Elastic Store option is used in off-net extension applications with analog modems to compensate for
small timing phase drifts that typically occur in such applications. A "cross-over" cable is required to
connect the MultiDSU56K DTE connector to the analog modem in this application.
The analog modem at the same end as the MultiDSU56K must have External Timing enabled; the modem
at the end of the off-net extension must have DDS Timing enabled.
In MultiDSU56K applications that use controlled carrier, the CTS delay for the analog modem at the end of
the off-net extension must be longer than the CTS delay of the MuII1DSU56K.
An example of a typical off-net extension application is shown in Appendix A of this manual.
82017502
Wire Gage
19AWG 22AWG
22.0 15.0
19.0 13.0
15.0 10.0
11.9 7.0
10.0 6.0
24AWG 26AWG
12.0 9.5 miles
10.0 8.0 miles
7.0 5.5 miles
5.0 4.0 miles
4.2 3.0 miles
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