Red Lion LEGEND - Manual (Page 49)

SERIAL CONNECTIONS
When wiring, remove the 12-position terminal block, which is on the top board
at the rear of the unit. Refer to the top label and configure the RS485/RS232
jumpers for the desired interface. Then, refer to the numbers listed on the label with
the terminal description for installing each wire in its proper location.
For RS-485 the data (transceiver) wires connect to the A (+)/TXD and B
(-)/RXD 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 transceiver lines. The signal ground is connected
from only one Legend Plus to the equipment. If necessary, the shield can be used
as the signal ground.
TERMINAL DESCRIPTIONS
COMM. - Common required for some applications.
A (+)/TXD & B (-)/RXD - The Legend Plus transmits and receives on these
two terminals which are connected to the external device.
TX EN. - Used primarily with a Red Lion Controls (RLC) GCM422 module to
interface with an RLC model DMPC printer or connect Legend Plus units in a 20
mA communication loop with other units.
For connection to a GCM232 Converter Module, refer to the diagram below.
For connection to an RS232 port on a computer, refer to diagrams below.
When all connections are made, replace the terminal block into its proper location.
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