Advantech ADAM-5511 Manual page 107

There are two LEDs for each port on the front panel of the ADAM-
5090 to display specific communication status:
a. Green LED (RX): Data Receiving Status; the LED indicator is on
when the port is receiving data.
b. Orange LED (TX): Data Transmitting Status; the LED indicator is
on when the port is transmitting data.
This section explains how to configure an ADAM-5090 module before
implementing it into your application.
Step 1: Get your host PC ready, and run the ADAM-5510 Utility
Software.
Step 2: Install the ADAM-5090 Module and power on your ADAM-
5510 main unit.
Step 3: Download the executable program to the main unit
Step 4: Monitor the ADAM-5090 Module's current status from the PC
through the utility software.
main ()
{
//Install the port you would like to use. Here we install slot 0, port 1.
port_install(1);
// Here we install slot 2, port 2.
port_install(22);
//Set port data format.
//Here we set the data format of port 1 as lengh:8; parity:0;stop_bit:1. (N81)