ASM-10/8
Sync/Async Short Range ModemFEATURESn

Synchronous orasynchronousn

Full or half duplexn

Selectable data rates up to19.2 kbpsn

Extended range up to 28 km(17.5 miles)nDifferential diphasemodulationn

Carrier control for multipoint
operationnV.54 diagnostics including
unattended remote testnDetects power failure in theremote unitnLine protection circuitsn

Low power consumption

DESCRIPTIONn

The modem uses conditioned
differential diphase modulation(EUROCOM Std. D1), which provides
immunity to background noise, andeliminates normal line distortion for
efficient transfer of serial data overtwisted pair cable. ASM-10/8 iscoupled to the dedicated line throughisolation transformers which, inconjunction with other circuitry,protect against AC or DC
overvoltage. The protection circuitry
enables operation even when DC isconnected to the line.

nTransmit level and impedance areindependently selectable. Transmit
timing can be provided internally, or
can be derived externally from thedata terminal or from the receive
signal. Receive timing is regenerated
from the data. Line communication isalways synchronous. When set toasync mode, ASM-10/8 performs
async to sync conversion incompliance with ITU V.14 standard.

nn

The ASM-10/8, Short Range
Modem, operates full or half duplex
with synchronous or asynchronoustransmission format overunconditioned dedicated lines.
ASM-10/8 has an extended range ofup to 28 km (17.5 miles) andoperates at eight selectable data
rates up to 19.2 kbps.

nASM-10/8 features V.54
diagnostic capabilities for performing
local analog loopback, local andremote digital loopback. The operator
at either end of the line may test bothmodems and the line when in thedigital loopback mode. The loopback
is controlled by either front panel
pushbuttons or via Pins 18 and 21 ofthe V.24/RS-232 interface. A
selectable option allows insertion of adelay into the data stream so that theV.54 loops are not carried across thenetwork.
ASM-10/8 is available as adesk-top unit or as a rack-mount card
for a 19" rack. The rack can carry up
to 14 of the ASM-10/8 cards. The
rack-mount card can detect andindicate power failure on the remotestand-alone unit. The front panel RPF
indicator lights if remote power failureoccurs.

SPECIFICATIONSn Transmission LineType:
Unloaded twisted pair:
19 to 26 gauge
2W for half duplex
4W for full duplex
Range: (see Table 1)
Level:
0 dBm, -3 dBm, -6 dBm, -9dBm
Impedance:
150, 300, 600ΩΩ
Strap-selectable
Return loss:
Greater than 15 dB
Carrier:
Controlled by RTS orconstantly ON
Modulation:
Differential diphase,
Eurocom Std. D1
n Digital Interface
Type:
EIA RS-232-C/ITU V.24
Data Rates:
Sync and async selectable
1.2, 2.4, 3.6, 4.8, 7.2, 9.6,14.4, 19.2 kbps
RTS/CTS delay:
Strap-selectable
0, 8 or 64 msec
n Diagnostics
Complies with V.54 standard
Digital loopback:Local (DIG), activated bymanualpushbutton
Remote (REM), activated bymanual pushbutton or by DTE
interface signal, Pin 21
Analog loopback:Local (ANA), activated bymanual pushbutton or by DTE
interface signal, Pin 18

n Timing Elements

Receive clock: derived from CDP
receive signal
Transmit clock: derived from
3 alternative sources:– Internal− External from terminal, via
Pin 24− Loop clock, derived fromreceive signal, looped backas transmit clock.
n Indicators
TD –Transmit DataRD –Receive Data
RTS – Request to Send
DCD – Data Carrier Detect
TEST – Test
PWR – PowerRPF – Remote Power Fail(ASM-10/8/R only)n PhysicalASM-10/8/SA Modem:
Height:
44 mm / 1.7 in
Width:
215 mm / 8.5 in
Depth:
243 mm / 9.5 in
Weight:956 gm / 2.1 lb
ASM-10/8/R Card:
Length:230 mm / 9.0 in
Width:
157 mm / 6.2 in
Height:25 mm / 0.9 in
Weight:
284 gm / 0.6 lb
ASM-MN-214 Rack:Height:
178 mm / 7.0 in
Width:
480 mm / 19.0 in
Depth:
216 mm / 8.5 in
Weight:4.0 kg / 8.8 lb
n Power Supply
115 or 230V (±10%)
47 to 63 Hz; 3W
n Protection
AC/DC overvoltage protection
circuits are connected via
transformers to transmit andreceive lines.

n Environment

Temperature: 0-50°C / 32-122°F
Humidity:
up to 90%,
non-condensing
Table 1. Approximate Range
DataRatekbps

19 AWG(0.9 mm)
km miles

24 AWG(0.5 mm)
km miles

26 AWG(0.4 mm)
km miles

19.2

22.5

14.0

10.0

6.2

7.5

4.7

14.0

24.5

15.3

11.0

6.9

8.2

5.1

9.629.0

18.1

13.0

8.1

9.5

5.9

7.2

33.0

20.5

15.0

9.4

11.0

6.9

4.8

36.0

22.5

16.0

10.0

12.0

7.5

3.6

40.0

25.0

18.0

11.2

13.5

8.4

2.4

47.0

29.3

21.0

13.1

15.7

9.8

1.2

55.0

34.3

28.0

17.5

21.0

13.1

ORDERING
ASM-10/8/SA/*
Short Range Modem, stand-alone
unit with internal power supply
ASM-10/8/R
Short Range Modem card for
ASM-MN-114 19" modem rack
ASM-MN-214/+/&19" modem rack for 14 cards*Specify stand-alone power supply:
115 for 115 VAC
230 for 230 VAC+ Specify rack main power supply:
115 for 115 VAC
230 for 230 VAC
48 for -48 VDC& Specify rack secondary power
supply:(Same options as the mainpower supply.)

Specifications are subject to change without prior notice.

APPLICATION

600-100-11/97
 1997 RAD Data Communications Ltd.