Clarity Bay Cat X SN-4620-1080 Manuel D’Utilisation

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2.6 Connecting RS232 Communication

RS232 communication allows a computer to control one or 
more units using the computer’s serial port. Almost every-
thing you can do with the remote, you can do with RS232 
commands. Plus, you can send inquiries to the units and 
find out the current settings and values. 

To connect a computer to the first unit, use an adapter on 

the computer’s serial port connector to convert this to an 
RJ45 connector. 

1. Obtain an adapter that has a female 9-pin connector. 

2. Wire it as shown in the illustration and table below. 

Only three wires are required. Clip off the other wires, 
or tuck them into the connector body. 

Use Cat-5 cable to connect from the computer (with the 

adapter in place) to the first unit’s RS232 In connector. 

From the first unit, connect RS232 Out to the next unit’s 

RS232 In. Continue in this way until all units are in the 
loop. The order of units in the loop does not matter because 
each unit in the array must have a unique address.

✎

The loopthrough limit is approximately 30 units in 
typical situations. However, if the units are spaced 
far apart or the total length of the loopthrough is 
very long, this limit may be reduced. You may 
need multiple RS232 sources.

Each unit in the loop must have a unique RS232 ID. 

Open the Serial Port Settings menu for each unit. On the 

1

2

3

4

6

7

9

8

5

To go from 9-pin D-sub serial connector on the back of 
the ccomputer to an RJ45 connector, use a standard 
RJ45-to-9-pin adapter. Wire it internally as shown. The 
wiring shown for this adapter is correct for straight-thru 
cables. Straight-thru cables are wired 1-to-1, 2-to-2, etc. 

Yellow wire

pin 3

Black wire

pin 2

Green wire

pin 5

RJ45

9-pin

6

3

5

5

3

2

female 9-pin

RJ45 looking into the socket.