Owner`s manual

MT56DSU2 Owner’s Manual
82017502 15
Chapter 3 – Operation
3.1 Introduction
This chapter provides information on the operating functions of the MultiDSU56K. During normal
operation the MultiDSU56K requires no operator intervention.
Many of the optional features of the MultiDSU56K are selected by setting a DIP switch on the PC board.
Please refer to Changing the Default DIP Switch Settings (Chapter 2) to change your particular
environment.
3.2 Options
The switchable features of the MultiDSU56K are:
• Data Rate • Clocking
• Async/Sync • RTS Forced On
• Anti-Streaming • DSR Forced On
• Elastic Store • Async Word Length
• System Status • NormaL/Diagnostics
• Circuit Assurance
The MultiDSU56K has a pre-configured (default) setting for each of these options when shipped from the
factory. Refer to Chapters 2 and 4 of this manual for further information regarding these option DIP
Switches. The following sections describe the option in terms of the operation of the MultiDSU56K in a
DDS or other 4-wire network.
3.2.1 Data Rate
This option allows selection of the MultiDSU56K’s data transmission rate. The data rate selected here
must match the DDS or other 4-wire network line rate that you subscribed for with your telco.
The default for this function is a data rate of 56K bps. (Refer to Chapter 2 for option switch selection.)
3.2.2 Async/Sync
This option allows selection of the MultiDSU56K’s type of data transmission used. The transmission type
selected here must match the DTE. The default is “sync” (synchronous data transmission).
3.2.3 Anti-Streaming
This option is typically enabled on remote DSUs using multi-point lines. When enabled, the anti-streaming
feature prevents a streaming (“jammed”) DTE from affecting communications from remote sites (in a
multi-point circuit) that are operating properly.
When Anti-Streaming is enabled, the MultiDSU56K will detect when the DTE device holds RTS (Request
To Send) on for longer than 20 seconds. The MultiDSU56K then forces RTS and CTS off internally and
sends the DDS Idle Channel signal to the network. The DTE’s interface is ignored until the streaming DTE
is repaired. The front panel RTS LED is continuously lit and the CTS LED is off when a streaming DTE
has been detected.
The default for this function is Anti-Streaming disabled. (Refer to Chapter 2 for changing the default DIP
switch settings.)