ASMi-31
Sync/Async 2-Wire Manageable IDSL ModemFEATURES• 2-wire IDSL modem withremote management,
extending data transmission
to 7.0 km (4.3 miles)• Supports multiple data rates
between 1.2 and 128 kbps
• Utilizes 2B1Q line coding
for extended range andimproved quality• Provides full duplex inband
management of the remote
unit over the D-channel• Supports variety of datainterfaces, as well as built-in
Ethernet bridge and router• Operates with internal,
external or receive timing,
providing automatic rate
detection in external clockmode• Operates opposite RAD’s
ASM-31, ASMi-31CQ (quadmodem card for LRS-24
modem rack), SRM-31,
HS-U modules of Megaplex,
U-RPT repeater• Supports V.54 diagnostics

and BER testing• Provides real time alarmindication for local andremote units• Available as a single modem
card for RAD’s LRS-24
modem rack with SNMP
management and for theASM-MN-214 modem rackASMi-31
Sync/Async 2-Wire Manageable IDSL ModemDESCRIPTION• The master modem provides full

• ASMi-31, IDSL modem withremote management, operates infull duplex over 2-wire lines,extending data transmission to
7.0 km (4.3 miles) irrespective ofdata rate.

• ASMi-31 supports synchronous or

asynchronous operation atuser-selectable data rates from 1.2
to 128 kbps.

• The modem uses 2B1Q line code
and adaptive equalizers, which
provide immunity to backgroundnoise, eliminate normal line
distortion and enable efficienttransmission over 2-wire twisted
pair cables.

• ASMi-31 is available as “master”

or “slave” standalone units. The
master modem includes front
panel LCD and control buttons.
The slave modem has a blankfront panel with a special 20-pin
connector for a portable control
unit (PCU) connection.

duplex inband management of theremote unit. The management
data is transmitted over theD-channel to ensure simultaneousconfiguration of the local andremote units, activation ofreal-time alerts on system faults
and initiation of the diagnostic
tests.

• ASMi-31 supports a wide range ofdigital interfaces: V.24/RS-232,
V.35, X.21, RS-530, V.36/RS-449
and G.703 Codirectional(64 kbps). In addition, the modem
supports built-in Ethernet bridge(IR-ETH), Ethernet bridge withVLAN support (IR-ETH/Q) and IP
router (IR-IP), which allow
LAN-to-LAN connectivity using
IDSL technology.

• The ASMi-31 clock source

depends on the modem's
functional mode (master or slave):
Master clock: INT, derived frominternal oscillator or EXT,
derived from the DTE interface
Slave clock: RCV (recoveredfrom line signal).

• The carrier may be continuous orcontrolled by RTS, for passing
control signals end-to-end(user-selectable).

• ASMi-31 has wide diagnostics

capabilities that include thefollowing test options:
V.54 local analog and remote
digital loopbacks
BER testing as per V.52.

• Line interface circuitry protects
against lightning and powersurges.

• ASMi-31 can be managed via

front panel buttons and LCD(in the master unit). The single
modem card, installed into theLRS-24 rack can be managed via
an SNMP-based network
management station.

APPLICATIONSCentral Site

Site A
2-wireV.35
RouterASMi-312-wireV.35

LRS-24ASMi-31

RouterPublicNetworkSite B
ASMi-31CQ
2-wireV.35
RouterASMi-31

SNMP
ManagementStation2-wire

V.35
ASMi-31

Figure 1. Standalone ASMi-31 units operate opposite ASMi-31CQ quad modem card
installed into the LRS-24 modem rack.

RouterASMi-31
Sync/Async 2-Wire Manageable IDSL ModemSPECIFICATIONSLINE INTERFACEDTE INTERFACE

GENERAL• Type• Timing

V.24/RS-232: 25-pin D-type,female
RS-530: 25-pin D-type, female
V.35: 34-pin, female
X.21: 15-pin, D-type, female
V.36/RS-449: via adapter cableconverting between the RS-530
connector and a 37-pin, D-type,female connector
G.703 Codirectional: RJ-45 or
terminal block
IR-ETH (Ethernet bridge): RJ-45or BNC coax
IR-ETH/Q (Ethernet bridge withVLAN support): RJ-45
IR-IP (IP router): RJ-45• Line Type

Unconditioned telephone line
(twisted pair), 19 AWG to26 AWG• Line Coding
2B1Q• RangeUp to 7.0 km (4.3 miles) over
24 AWG line, irrespective of datarate• LevelUp to 14 dBm• Impedance
135Ω, high• Data Rate

• Return Loss

Synchronous: 1.2, 2.4, 4.8, 9.6,
16, 19.2, 32, 38.4, 48, 64 or
128 kbps
Asynchronous: 1.2, 2.4, 4.8,9.6, 19.2, 38.4, 57.6 or
115.2 kbps

Greater than 15 dB• StandardLine code and transmission
specifications comply withANSI T1.601, 1988

• Carrier• Control Signals

Constantly ON or controlled byRTS• Connector

3-clip terminal block andRJ-45 jack

DCD:
ON when two modems aresynchronized
Local unit DCD follows remote
unit RTS
DSR:
Always ON
Remote unit DSR follows local
unit DTR

Master clock:Internal – supplied by theinternal oscillator
External – received from theDTE
Slave clock:
Receive – recovered from theline signal• Diagnostics

V.54 local analog and remote
digital loopbacks
V.52 BER testing

Note: The loopbacks are initiated by themanagement software or via the DTE interface
pins. Activation via the DTE interface pins is notavailable for X.21, G.703 or Ethernet interfaces.

• Indicators

PWR (green) – PowerRTS (yellow) – Request to Send
DCD (yellow) – Data CarrierDetectTD (yellow) – Transmit Data
RD (yellow) – Receive Data
ALM (red) – Alarm
TST (red) – Test
SYNC (green/red) – Sync Status

Megaplex-2200
6 km (3.7 miles)

6 km (3.7 miles)

HS-U-12
Phantom-Fed
U-RPT

ASMi-31
DTE

Ringer-2200

Figure 2. ASMi-31 working opposite the HS-U-12 module of Megaplex.
The HS-U-12 ISDN data module provides power feeding for remote U-RPT repeater, increasing the IDSL operation
range for up to 12 km (7.4 miles)

ASMi-31
Sync/Async 2-Wire Manageable IDSL Modem• PhysicalHeight:Width:
Depth:
Weight4.4 cm
21.5 cm
24.3 cm
1.5 kg/ 1.7/ 8.5/ 9.6/ 3.2

inininlb• Power

AC: 100 to 240 VAC (±10%),50 or 60 Hz
DC: 24 VDC (18 to 36 VDC), or-48 VDC (-36 to -72 VDC)

ORDERING

PCU
Portable control unit with protective
casing for the slave ASMi-31 unit orASMi-31/R card

ASMi-31-2/M/*/#
Sync/async 2-wire manageable IDSL
modem, master unit

RM-28
Special hardware for mounting one or
two ASMi-31 units in a 19-inch rack

ASMi-31-2/S/*/#
Sync/async 2-wire manageable IDSL
modem, slave unit

• Power Consumption

ASMi-31-2/R/#
Single modem card for ASM-MN-214
rack• Line Protection

ASMi-31-2CF/#
Single modem card for LRS-24 rack,
ETSI version

Standalone ASMi-31: 5W
ASMi-31/R, ASMi-31C: 2.2W

AC/DC overvoltage protection
circuits are connected via
transformers to the transmit andreceive lines• Environment

Temperature: 0–50°C/32–122°F
Humidity:
Up to 90%,
non-condensing

ASMi-31-2CB/#Single modem card for LRS-24 rack,
ANSI version* Specify power supply:
AC for 100 to 240 VAC
48 for -48 VDC
24 for 24 VDC# Specify DTE interface:
V24 for V.24/RS-232 interface
V35 for V.35 interface
V36 for V.36/RS-449 interface
530 for RS-530 interface
X21 for X.21 interface
703 for G.703 Codirectional(64 kbps) interface with terminal
block connector
703/RJ for G.703 Codirectional(64 kbps) interface with RJ-45connector
UTP for IR-ETH module with
RJ-45 connector
BNC for IR-ETH module with
BNC connector
UTP/Q for IR-ETH/Q module
IP for IR-IP module
Note: ASMi-31/R cards use DB-25 DTE
connector of the ASM-MN-214 modem rack.

646-100-11/02

 1989–2002 RAD Data Communications Ltd.
All other trademarks are the property of their respective holders.

Specifications are subject to change without prior notice.