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What is the recommended RS232 to RS485 Adapter for all Berger Lahr Legacy PRODUCTS?

Goals and Symptoms

Due to the original Berger Lahr Model MP923 RS232 to RS485 adapter being obsolete and no longer available some customer may find a need for a suitable replacement product.
Thisresolution provides detailed information on a suitable replacement product that has been tested and verified for functionality with all Berger Lahr legacy PRODUCTS that use RS485 communication ports.

Facts and Changes

The Telebyte Model 245 Opto Isolated Superverter is an RS232 to RS485 adapter that has been tested and proven to be compatible with Berger Lahr RS485 communication.

Unlike the original Berger lahr MP923 product which was supplied with pre-wired cables for connecting the adapter, use of the Telebyte adapter requires some minor wiring so users must have basic wiring skills.

Causes and Fixes

When using the Telebyte Model 245 RS232 to RS485 adapter with Berger Lahr legacy PRODUCTS the following wiring arrangement should be used.

T+ pin 14 of the Telebyte adapter connected to pin 9 of the RS485 port of the Berger Lahr product
T- pin 2 of the Telebyte adapter connected to pin 4 of the RS485 port of the Berger Lahr product
R+ pin 16 of the Telebyte adapter connected to pin 8 of the RS485 port of the Berger Lahr product
R- pin 3 of the Telebyte adapter connected to pin 3 of the RS485 port of the Berger Lahr product.
Gnd pin 7 of the Telebyte adapter connected to pin 5 of the RS485 port of the Berger Lahr product

The DIP switch settings on the Telebyte Model 245 adapter should be configured as follows.

SW1 A = off, SW1 B = off, SW1 C = on, SW1 D = off
SW2 A = off, SW2 B = off, SW2 C = on, SW2 D = off

DCE/DTE switch should be set for DCE

SW1
SW2
Mode
A
B
C
D
A
B
C
(1)
(2)
(3)
(4)
(1)
(2)
(3)
1) RS-422
OFF
OFF
OFF
OFF
OFF
OFF
ON
2) RS-485
OFF
ON
OFF
ON
OFF
OFF
ON
Four-wire transmitter enabled by RTS
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3 ) RS-485
ON
OFF
OFF
ON
OFF
OFF
ON
Four-wire transmitter enabled by DTR
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4) RS-485
OFF
OFF
ON
OFF
OFF
OFF
ON
Four-wire transmitter enable by TD
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5) RS-485
OFF
ON
OFF
ON
X
ON
OFF
Two-wire transmitter enabled by RTS
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6) RS-485
ON
OFF
OFF
ON
X
ON
OFF
Two-wire transmitter enabled DTR
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7) RS-485
OFF
OFF
ON
OFF
X
ON
OFF
Two-wire transmitter enabled by TD
text text text text text text text text


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