Lesson 2: Establishing Communications
Objectives:
• Add and configure a serial port tag; and
• Add and configure an I/O device driver tag.
Lesson 2 Overview
Having created a VTS application, you can begin to build the tags that will be associated with the equipment in the physical system. The first step in doing so is to enable communications between the VTS application running on your PC, and the I/O device that reads and writes data to and from the equipment in your physical system. This is done by building two essential communication tags:
• A port tag (in this case, a serial port tag)
• An I/O device driver tag.
The role of a serial port tag is to open a port on your PC for communications. In an actual system, this would be the port to which the I/O device is connected. A second essential tag is required to enable your application and the physical I/O device to communicate: an I/O device driver tag.
There are many device driver tags built into VTS. The type you use for your own applications will depend upon the brand of I/O device, as well as its protocol.
As described in our system plan, we are using a simulated I/O device to generate computer-generated data for our tutorial application; this I/O device is a virtual Modicon PLC.
Creating, organizing, and managing the tags in your application is done with the Tag Browser tool. You will be using the Tag Browser frequently throughout the tutorial and will have the opportunity to work with all of its functions.
Estimated Time
It is estimated that Lesson 2 will take approximately 15 minutes to complete.
2.1 Adding a Serial Port Tag