- The ASM-31, all-rate, sync/async short range modem,
operates full duplex over 2-wire twisted pair, at selectable data rates
from 1.2 kbps up to 128 kbps.
- ASM-31 operates using 2B1Q line coding, and
provides an operating range of up to 5.5 km (3.4 miles), independent of
the data rate. An adaptive equalizer provides noise immunity and high
performance over low quality lines.
- Full duplex operation is achieved using the echo
cancellation technique. This method entails setting one modem to be Master
clock and the other to be Slave clock.
- ASM-31 features diagnostic capabilities including
implementation of local and remote loopbacks. The operator at either end
of the line may test both modems and the line in a number of loopback
modes. The loopbacks are controlled by either a manual switch or from the
- The modem also includes a BER tester for complete
end-to-end integrity testing. An error LED indicates each bit error
- Front panel LEDs provide indication for TD, RD, RTS
and DCD, as well as Power, Local and Remote Test and Sync Loss.
- Interface options include V.24/RS-232, V.35,
RS-530, X.21, G.703 Codirectional, and Ethernet (see Ordering). The analog
line connection is provided via an RJ-45 or a 3-port terminal block.
Configuration is via internal jumpers and straps.
- Line interface circuitry protects against lightning
and power surges.
- ASM-31 is available as a standalone unit or as a
card for mounting in the ASM-MN-214, 19" rack. The rack can carry up to 14
- 2-wire, all-rate short range modem
- Single sync/async channel
- Full duplex operation using echo cancellation
- Selectable data rates:
Sync: 1.2 kbps to 128 kbps Async: up to 38.4 kbps
- 2B1Q line coding
- Operating range up to 5.5 km (3.4 miles),
independent of data rate
- Diagnostics include internal BERT, local and remote
- DTE interfaces:
V.24/RS-232, V.35, RS-530, X.21, G.703 Codirectional, and IR-ETH
2-wire, standalone modem
2-wire modem card for
ASM-MN-214, 19" rack
||Specify power supply:
115 for 115 VAC supply
230 for 230 VAC supply
48 for -48 VDC supply
24 for 24 VDC supply
V24 for V.24/RS-232 interface
V35 for V.35 interface
X21 for X.21 interface
530 for RS-530 interface
G.703 for G.703 Codirectional
UTP for built-in Ethernet/802.3 bridge with RJ-45 connector
BNC for built-in Ethernet/802.3 bridge with BNC connector
Note: When using V.35 or X.21 interface for
ASM-31/R, the CIA adapter is required.
Connector Interface Adapter for the
ASM-MN-214 19" rack
V35/1 for adapting one modem card's 25-pin connector into one
V.35, 34-pin connector
X21 for adapting two adjacent modem cards' 25-pin connectors to
two X.21, 15-pin connectors