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CHAPTER 2: Introduction
2. Introduction
2.1 Functional Description
The MiniStat-Four is an advanced, full-function miniature statistical multiplexor.
It multiplexes four asynchronous data sub-channels at data rates of 300 to
19,200 bps onto a single composite synchronous channel. An external clock signal
automatically determines the composite channel rate, but you select sub-channel
characteristics and other system features using a menu-driven configuration
function.
The mux uses dynamic data-buffer management to allocate available buffer
capacity according to sub-channel activity. Powerful and efficient error detection
and automatic retransmission, which are completely transparent to the user,
ensure error-free end-to-end data transmission.
Independent hardware and software flow control are used for each sub-channel
(both end-to-end flow control [DTE to DTE] and terminal flow control [DCE to
DTE]). For compatibility with most applications, choose from several software
flow-control characters.
From any sub-channel port, the mux provides for full system configuration
(including configuration downloading from the local MiniStat-Four to the remote
MiniStat-Four, and vice-versa). Password protection prevents unauthorized
configuration changes.
Configure the mux from any standard PC or CRT terminal, using a simple, menu-
driven facility. Nonvolatile memory contains configuration parameters, which are
immediately available upon power-up.
To make initial system configuration easier, the MiniStat-Four stores—in addition
to the user-selected configuration—a set of default configuration parameters
(factory settings) that you can select via a jumper.
The mux gives you comprehensive diagnostics functions, including automatic
self-test upon power-on, local and remote sub-channel loopback, and local and
remote composite-channel loopback. LED indicators show the condition of each
sub-channel and composite-link synchronization status. In addition, the MiniStat-
Four can control the V.54 pins (pins 18 and 21) of the RS-232 interface serving the
composite link, thereby allowing control of analog- and remote digital-loopback
functions of the modem connected to the mux.
