Port Numbers

One final piece of information is required in order for the response to find its way back to the device enabler. The IP address gets the response UDP packet to your computer but now it must find its way to the device enabler application. This is done via a Port Number. The device communication enabler connects its socket to a Port Number. This connection processed is called binding. The operating system will permit only one application per computer to bind to a given port number.

You configure the controllers to send their responses to this port number. The default FINS UPD Port Number for the OMRON Ethernet Modules is 9600. You instruct the device communication enabler to bind to this number by configuring a Service Name.

The Service Name is resolved to a number in a manner similar to the host name's resolution to an IP address. It is looked up in an operation system file called the services file when the device communication enabler is first started.

You must add an entry to the services file relating a service name to a UDP port number which is the same as the UDP Port Number programmed in your OMRON Ethernet Modules. Contact your system administrator or the network manuals for the operating system for instructions on modifying this file.

You tell the device communication enabler which name to look up (to find the UDP port number) through the CIMPLICITY project's global parameters. See Setting Required Protocol Parameters for further instructions on how to do this.

More information

    OMRON TCP/IP application notes.