Serial port pinout

The AlphaCom E exchanges has two serial ports. In AlphaCom E20 and E26 they are available on RJ45 connectors. In AlphaCom E7 the serial port 0 is on a 9 pin DSUB connector, and the serial port 1 is on a RJ45 connector.

The serial port 0 is RS232 only, the serial port 1 can be RS232, RS422 or RS485.

Pinout of the RJ45 connector:

RJ45 pinout
RS232	3 = TX<br\>6 = RX<br\> 4&5 = GND
RS422	1 = RX-<br\>2 = RX+<br\>7 = TX-<br\>8 = TX+
RS485	1/7 = Data - <br\> 2/8 = Data+

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Adaptor cable from RJ-45 to 9-pin Female D-SUB:

RJ45 - AlphaCom E	9 p Female DSUB
3	2
5	5
6	3

Cabling between RIO unit and AlphaCom E using multidrop RS485:

 AlphaCom               RIO #1                  RIO #n           
 Serial 1             15 pin DSUB             15 pin DSUB
  RJ45

   1 -----------------+-- 9 --+----------------+-- 9
                      |       |                |
                      --- 11---                --- 11

   7 -----------------+-- 2 --+----------------+-- 2
                      |       |                |
                      --- 4 ---                --- 4

In the 15 pin DSUB of the RIO unit pin 2 & 4 and 9 & 11 must be connected together.