Specifications

Chapter 1. Introduction ASMi-31 Installation and Operation Manual
1-4 Functional Description 16-03-00 15:51
Remote
Management
The ASMi-31 standalone modem is very conveniently managed from the
master station by means of RADview, a RAD SNMP application. This
user-friendly graphical user interface manages the ASMi-31C modem cards
installed in the LRS-12 or LRS-24 hub and, through them, the ASMi-31
standalone units.
Both data and management are transmitted inband over the same line,
simultaneously, without interference.
Data
Transmission
Full duplex operation over 2-wires is achieved using the adaptive
"echo-canceling" technique. The ASMi-31 modem uses 2B1Q line coding
to achieve the range of 8 km/5 miles, for all data rates. This coding
provides immunity to background noise, eliminates normal line distortion
and permits efficient transmission over 2-wire twisted cables.
An adaptive equalizer provides noise immunity and high performance over
low quality lines.
Special
Management
Configurations
The ASMi-31 standalone modem unit has internal jumpers which allow for
special management configurations such as point-to-point applications
without ASMi-31C modem cards in the LRS-12 or LRS-24 hub, and also
on-site diagnostics testing.
Diagnostic
Capabilities
In addition to the remote diagnostic capability, the ASMi-31 standalone
modem provides diagnostic capabilities which can be executed locally.
These include the Digital Loopback (RLB) and Analog Loopback (LLB)
diagnostics; they are executed via the DTE interface after the appropriate
jumpers are set. The ASMi-31 unit has a blank panel to prevent
unauthorized operation at the customer premises.
The local diagnostics are as follows:
•
Remote Digital Loopback – REM, activated by pin in DTE interface and
supported by respective standard.
•
Analog Loopback – Local (ANA defined by the standard as LLB),
activated by pin in DTE interface and supported by the respective
standard.
Note
The ASMi-31 loopbacks do not operate with the X.21 and G.703
(Codirectional) because they are not supported by these standards.
Overload
Protection
The ASMi-31 modem is coupled to the line through an isolation transformer
which protects against AC or DC overvoltages. The protection circuitry
permits operation even when DC is connected to the line.