Table of Contents
Advertisement
MT56DSU2 Owner's Manual
3.2.8 RTS Forced On
With this option enabled, the MultiDSU56K 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 multipoint lines (i.e., when continuous outbound "carrier on is desired). This option must
be disabled on the remote station of a multipoint installation.
When this option is disabled, the MultiDSU56K 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.)
3.2.9
DSR Forced On
When this option is enabled, the MultiDSU56K forces the DSR signal on continuously regardless of the
condition of the received DDS signal (008 or Test). The permanent DSR signal is used to eliminate
momentary link interruptions that may be interpreted by the DTE as a communications channel failure.
With this option disabled, the DSP is handled as described in the "System Status" section earlier in this
chapter.
The default for this function is DSP Forced On. (Refer to Chapter 2 for changing the default DIP switch
settings.)
3.2.1O Async Word Length
This option allows you to select the word length to be used by the MultiDSU56K for asynchronous data
transmissions. The Async Word Length selections are 9-, 10- and 11-bits. The async word length selected
here must match the async word length set at the DTE.
The default for this function is a 10-bit async word (1 start, 8 data, no parity, 1 stop bit) length. (Refer to
Chapter 2 for changing the default DIP switch settings.)
3.2.11 Normal/Diagnostics
The default for this option is "Normal" (standard CSU/DSU operation). For information on the
"Diagnostics" selection, refer to Chapter 4.
3.3 LED Indicators
The front panel of the MuIt1DSU56K contains twelve LED indicators that can help in troubleshooting
network or device problems. Chapter 4 of this manual contains detailed information on the LED indicators.
3.4 Functions
This section describes the two optional MultiDSU56K modes of operation. The MultiDSU56K can be used
as either a point-to-point Local Area Data Set (at speeds up to 56K bps), or in an off-net extension
application using conventional analog lines and modems (to complete DDS communications in areas
without DDS availability).
3.4.1 Local Area Data Set Applications
Your MultiDSU56K can be used as a point-to-point LADS (Local Area Data Set) at transmission speeds of
2400, 4800, 9600, 19200 or 56000 bps over 4-wire, non-loaded metallic wire pairs.
The MultiDSU56K conforms to the signal power requirements of Bellcore Pub. 41028 (data sets used on
LADC), when used at subrate speeds (less than or equal to 19200 bps). The MultiDSU56K does not meet
this requirement at the 56K bps rate. The 56K bps rate may be used in applications with customer-supplied
lines, or lines not covered by Pub. 41028, or other tariff requirements.
The installation of the MultiDSU56K in a LADS application is the same as for DDS applications, except
for the timing (Clocking) setting. LADS applications require one MuIt1DSU56K to be set for Internal
timing and the other MuIt1DSU56K to be set for DDS timing (refer to Chapter 2 of this manual). The
network cable connection requires "cross-over' wiring, the transmit pair of each MultiDSU56K must be
connected to the receive pair of the far-end MultiDSU56K.
82017502
17
Advertisement
Table of Contents
