Multitech MT56DSU-R, Owner'S Manual

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Chapter 3 - Operation
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3.2.7 Clocking
This option allows selection of the MT56DSU-R’s clocking (timing for
synchronization) from one of three sources. These clocking sources
are discussed below.
Internal clocking enables the MT56DSU-R to accept timing from its
internal timing oscillator.
External clocking allows the MT56DSU-R to derive timing from any
external device that can supply timing to the External Transmit Clock
line on the MT56DSU-R’s DTE interface connector. This external
clock must be within 0.008% of the nominal data rate.
DDS timing allows the MT56DSU-R to accept timing signals from
the DDS network’s receive bipolar signal. Use this selection
whenever the MT56DSU-R is connected to the DDS network lines.
The default for this function is DDS Clocking enabled. (Refer to
Chapter 2 for changing the default DIP switch settings.)
3.2.8 RTS Forced On
With this option enabled, the MT56DSU-R provides a continuous
CTS signal, disregarding the state of the RTS signal at the DTE
interface connector. This will provide a continuous outbound
indication to the network and remote (far-end) device that there is a
“Carrier on” condition.
For many (e.g., point-to-point) networks, it is best to maintain a
“carrier on” status on the communications channel to help minimize
line turnaround delays. This option is usually enabled for central site
DSU installations with multi-point lines (i.e., when continuous
outbound “carrier on” is desired). This option must be disabled on
the remote station of a multi-point installation.
When this option is disabled, the MT56DSU-R receives and uses
the RTS signal from the DTE.
The default for this function is RTS Forced On. (Refer to Chapter 2
for changing the default DIP switch settings.)
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