Red Lion LEGEND - Manual (Page 38)

SERIAL CONNECTIONS
When wiring, remove the 12-position terminal block, which is the top board at
the rear of the unit. Refer to the numbers listed on the top label with the terminal
description for installing each wire in its proper location.
The two data (transceiver) wires connect to the TX/RX (+) and TX/RX (-)
terminals.
It is recommended that shielded (screened) cable be used for serial
communications. This unit meets the EMC specifications using Alpha #2404
cable or equivalent. There are higher grades of shielded cable, such as, four
conductor twisted pair, that offer an even higher degree of noise immunity.
In some applications a signal ground may be required to establish a ground
reference. The signal ground is required if the equipment does not have internal
bias resistors connected to the RS485 transceiver lines. The signal ground is
connected from only one Legend to the RS485 equipment. If necessary, the
shield can be used as the signal ground.
When all connections are made, replace the terminal block into its proper location.
TERMINAL DESCRIPTIONS
COMM. - Common required for some applications.
TX/RX (+) & TX/RX (-) - The Legend transmits and receives on these two
terminals which are connected to the external device.
TX EN. - Used primarily to connect Legends in a 20 mA communication loop
with other units.
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