M I N I A T U R E

F I B E R 0 P T I C M O D E M S

12

M I N I A T U R E

S H O R T R A N G E M O D E M S /

 

SRM-3A

Ultra-Miniature Async Short Range Modem

S E R U T A I N I M

•RS-232/V.24 on 9-pin connector

•4-wire, full duplex

•Data rates up to 19.2 kbps

•Transformer-isolated

•No external power required

•Compatible with the SRM-5A and SRM-6A

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4-wire

SRM-3A

SRM-3A

 

Laptop

Mainframe

computer

The SRM-3A is an ultra-miniature asynchronous short range modem connecting full duplex asynchronous terminals to computers. Using 24 AWG and operating at 9.6 kbps, it has an extended range of

4.5km/2.8 miles. It typically operates at data rates up to 19.2 kbps.

The combination of the modem’s miniature size and the use of a 9-pin D-type connector makes it particularly suitable for PCs, for connecting laptop computers to a mainframe and for UNIX systems such as Unisys U6000/50.

The SRM-3A is coupled to the line through isolation transformers for protection against AC or DC overvoltages. SRM-3A operates without external power by drawing low power from the DTE data and control

signals. The modem will operate fully even if only Transmit Data is connected, i.e., without any control signals.

The modem connects to the DTE via a 9-pin connector, male or female. Connection to the line is via a 4-screw terminal block, RJ-11 jack or RJ-45 jack.

Approximate Range (for 24 AWG/0.5 mm)

Data Rate

 

 

kbps

km

miles

 

 

 

19.2

1.0

0.6

9.6

4.5

2.8

4.8

6.0

3.7

2.4

7.0

4.3

1.2

7.0

4.3

E R U T A I N I M / S M E D O M E G N A R T R O H

FOM-485

Miniature RS-485 Fiber Optic Modem

C I T P 0 R E B I F

•Converts from RS-485 to fiber

•Asynchronous transmission up to 115.2 kbps

•Transmission range up to 40 km (25 miles) over single mode fiber

•Full duplex over 4-wire or half duplex over 2-wire

•V.54 diagnostics

•LED indicators for status display

Visit www.rad.com for latest product updates

The FOM-485 is an asynchronous miniature fiber optic modem that transmits RS-485 signals over fiber optic cables. The FOM-485 is used in utility applications where there is a need to connect the main controller to a remote terminal unit (RTU).

The FOM-485 allows connection of up to

32 RTUs to a single host, at a wide range of data rates up to 115.2 kbps, at typical distances up to 40 km (25 miles) over single mode fiber.

The FOM-485 supports full duplex transmission over 4-wire or half duplex over 2-wire cables. It supports diagnostic capabilities complying with the ITU V.54 standard.

The modem has six LED indicators to display the status of the modem: TD, RD, DCD, RTS, TEST, and ERR.

S M E D O M

RS-485

Fiber

 

4-wire

 

 

FOM-485

FOM-485

RTU

 

 

Main

controller

RAD Data Communications 2006 Catalog

151