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Ordering Information

LDM2485A-P

Male DB-25 w/terminal block

LDM2485A-S

Female DB-25 w/terminal block

LDM2485A-PJ1

Male DB-25 w/RJ-11 jack

LDM2485A-SJ1

Female DB-25 w/RJ-11 jack

LDM2485A-PJ4

Male DB-25 w/RJ-45 jack

LDM2485A-SJ4

Female DB-25 w/RJ-45 jack

LDM2485A-P25S

Male DB-25 w/female DB-25

LDM2485A-S25S

Female DB-25 w/female DB-25

LDM2485B-P

Male DB-9 w/terminal block

LDM2485B-S

Female DB-9 w/ terminal block

LDM2485B-PJ1

Male DB-9 w/RJ-11 jack

LDM2485B-SJ1

Female DB-9 w/RJ-11 jack

LDM2485B-PJ4

Male DB-9 w/RJ-45 jack

LDM2485B-SJ4

Female DB-9 w/RJ-45 jack

Features

DB-9 (EIA-574) INTERFACE

POINT OR MULTIPOINT, OVER 2 OR 4 WIRES

POLLING ENVIRONMENT

EACH DIRECTION

“CONTROLLED BY RTS”

SURGE PROTECTION –STANDARD

LDM2485A and

LDM2485B

Signal Powered High Speed

RS-232 to RS-485 Converters

Dataforth’s Model LDM2485A & LDM2485B high speed, RS-232 to RS-

485 interface converters can turn your PC, terminal or other RS-232 device

into an RS-485 workstation. Operating over 2 to 4 wires, at data rates up to

115.2 kbps, Models LDM2485A & LDM2485B let your RS-232 machine talk

with up to 50 addressable devices in a multipoint polling environment. Since

multipoint environments can be difficult to work with, these products have

five separate configuration parameters (carrier control, RTS/CTS delay,

receive impedance, transmit-off impedance and echo) that allow you to fine

tune the converters to your particular application. And to keep your application

up and running, both models have built in surge protection. The Model

LDM2485A has a DB-25 connector for RS-232 environments, while the Model

LDM2485B has a DB-9 connector for EIA-574. Both models have several

options for twisted pair connection.

Specifications

Model

LDM2485A/LDM2485B

Transmission Format

Asynchronous

Data Rate Range

0-115.2K bps

Data Rate bps

115.2K

38.4K

9.6K

1.2K

Distance

mi

2.6

2.9

4.6

9.0

km

4.2

4.7

7.4

14.5

RS-232/EIA-574 Interface

DB-25/DB-9

RS-485 Interface Options

RJ-11 or RJ-45 jack or terminal block

with strain relief

Transmit Line

2, 4 wire unconditioned twisted pair

Transmit Mode

4-wire, full or half duplex; 2-wire half duplex

Control Signals

DSR turns “ON” immediately after the

terminal raises DTR; DCD turns “ON” after

recognizing the receive signal from the line;

CTS turns “ON” after the terminal raises RTS.

RTS/CTS delay

0 or 8 msec

Carrier

The carrier is switch selected either

continuous operation or controlled by RTS

Surge Protection

600W power dissipation at 1 ms

Power

Draws operating power from the RS-232 or

EIA-574 data and control signals; no AC

power or batteries required.

Temperature

32° to 122° F (0° to 50° C)

Size: 2485A

2.66" x 2.10" x 0.73" (68 x 53 x 19 mm)

Size: 2485B

2.50" x 1.20" x 0.75" (64 x 31 x 19 mm)

Weight

2 oz (57 gm)/1.4 oz (40 gm)

Dataforth does not authorize or warrant its products for use in life support/critical applications.