Features
- The ASM-20 Short Range Modem operates synchronously
or asynchronously (strap-selectable) at full or half duplex over
unconditioned lines. It has a range of up to 23 km (14 miles) and operates
at data rates from 19.2 kbps up to 256 kbps.
- The use of conditioned diphase modulation (EUROCOM
Std. D1) provides immunity to background noise, eliminates normal line
distortion and enables efficient transmission and reception of serial data
over twisted pair cable. Transmit timing is provided internally, or is
derived externally from the data terminal or receive signal. Receive
timing is regenerated from the data.
- When set to async mode, ASM-20 performs async to
sync conversion in compliance with ITU V.14 standard. Table 1 details the
rates relevant for sync and async. Rates higher than 115.2 kbps are
supported in sync mode only.
- ASM-20 features V.54 diagnostic capabilities to
perform local analog loopback, and local and remote digital loopback. The
loops can be manually activated from the front panel or via control
signals from the interface connector. In addition, ASM-20 incorporates a
built-in Bit Error Rate Tester (BERT) to enable complete testing of both
modems and the line. A front panel switch generates a pseudo-random test
pattern (511 bits) according to ITU V.52, for testing end-to-end
connectivity. An ERROR LED flashes when a bit error is detected.
- ASM-20 is available as a desktop unit or as a card
for the ASM-MN-214 modem rack. The rack can carry up to 14 ASM-20 cards
and is supplied with 25-pin D-type connectors.
- Optional hardware is available for mounting one or
two standalone units in a 19" rack.
Specifications
| Baud Rate |
19 AWG
(0.8 mm) |
22 AWG
(0.6 mm) |
24 AWG
(0.5 mm) |
26 AWG
(0.4 mm) |
| kbps |
km |
miles |
km |
miles |
km |
miles |
km |
miles |
| 256 |
3.75 |
2.3 |
2.85 |
1.75 |
2.25 |
1.4 |
1.9 |
1.2 |
| 192 |
6.0 |
3.7 |
4.5 |
2.8 |
3.5 |
2.2 |
2.7 |
1.7 |
| 144 |
10.6 |
6.6 |
6.75 |
4.2 |
4.5 |
2.8 |
3.4 |
2.1 |
| 128 |
12.4 |
7.7 |
7.3 |
4.5 |
5.0 |
3.1 |
3.6 |
2.2 |
| 115.2* |
12.8 |
7.8 |
7.65 |
4.75 |
5.25 |
3.3 |
3.8 |
2.5 |
| 112 |
12.8 |
8.0 |
8.0 |
5.0 |
5.5 |
3.4 |
4.0 |
2.5 |
| 96 |
13.0 |
8.1 |
8.3 |
5.15 |
6.0 |
3.7 |
4.15 |
2.6 |
| 72 |
15.0 |
9.3 |
9.4 |
5.8 |
6.25 |
3.9 |
4.3 |
2.65 |
| 64 |
17.6 |
11.0 |
11.0 |
6.8 |
7.5 |
4.6 |
5.3 |
3.3 |
| 57.6* |
18.8 |
11.7 |
11.75 |
7.3 |
8.0 |
5.0 |
5.6 |
3.5 |
| 56 |
18.8 |
11.7 |
11.75 |
7.3 |
8.0 |
5.0 |
5.6 |
3.5 |
| 48 |
19.4 |
12.0 |
12.2 |
7.6 |
8.25 |
5.2 |
5.8 |
3.6 |
| 38.4* |
20 |
12.5 |
12.5 |
7.8 |
8.5 |
5.3 |
6.0 |
3.7 |
| 32 |
20.5 |
12.75 |
12.85 |
8.0 |
8.75 |
5.4 |
6.2 |
3.85 |
| 28.8* |
20.5 |
12.75 |
12.85 |
8.0 |
8.75 |
5.4 |
6.2 |
3.85 |
| 19.2** |
23.0 |
14.0 |
14.0 |
8.7 |
9.75 |
6.0 |
7.0 |
4.3 |
ASM-20-2/*/+/#
Short range modem, stand alone unit
ASM-20-2R/+
Short range modem card for the
ASM-MN-214 19" rack
| * |
Specify power supply
115 for 115 VAC
230 for 230 VAC
48 for -48 VDC
24 for 24 VDC |
| + |
Specify interface
V24 for V.24/RS-232 (up to 64 kbps)
V35 for V.35
530 for RS-530
X21 for X.21
V36 for V.36/RS-449
703 for G.703 Codirectional (64 kbps)
UTP for built-in Ethernet bridge,
10BaseT with RJ-45
BNC for built-in Ethernet bridge, 10BaseT with BNC connector |
Note: When using V.35 or X.21 interfaces for
ASM-20-2R, the CIA adapter is required.
| # |
Specify G.703 Codirectional connector
TB for terminal block connector
RJ for RJ-45 connector |
RM-17
Hardware for mounting one or two standalone units in a
19" rack
CIA/&
Connector Interface Adapter for the
ASM-MN-214 19" rack
| & |
Specify CIA connector option:
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 |
Application
Figure 1 - Tail-end for Digital Network Application
Figure 2 - Point-to-point Application
ASM20-2/115/530
ASM20-2/115/G.703/RJ
ASM20-2/115/G703/TB
ASM20-2/115/UTP
ASM20-2/115/V24
ASM20-2/115/V35
ASM20-2/115/V36
ASM20-2/115/X21
ASM20-2/230/530
ASM20-2/230/G.703/RJ
ASM20-2/230/G703/TB
ASM20-2/230/UTP
ASM20-2/230/V24
ASM20-2/230/V35
ASM20-2/230/X21
ASM20-2/24/UTP
ASM20-2/48/UTP
ASM20-2/48/V35
ASM20-2/48/X21
ASM20-2R/530
ASM20-2R/V24
ASM20-2R/V35
ASM20-2R/V36
ASM20-2R/X21
ASM20/115/128/V35
ASM20/115/128/X21
ASM20/115/144/530
ASM20/115/144/V35
ASM20/115/144/X21
ASM20/115/64/V24
ASM20/115/G703
ASM20/230/128/530
ASM20/230/128/V35
ASM20/230/128/X21
ASM20/230/144/530
ASM20/230/144/V24
ASM20/230/144/V35
ASM20/230/144/X21
ASM20/230/64/V24
ASM20/230/G703
ASM20R/128/RS530
ASM20R/128/V35
ASM20R/128/V35/DC
ASM20R/128/X21
ASM20R/144/RS530
ASM20R/144/X21
ASM20R/64/V24
ASM20R/G703
ASM20R/G703/DC
|
