In Lesson 2, you discovered the process involved in establishing communications for an application. A serial port tag is required to facilitate communication between the actual I/O device and the I/O device driver tag within the VTS application.
While our tutorial application uses simulated data, the process involved in connecting a real I/O device to a VTS application does not differ. The list below provides you with a synopsis of the information you have learned in this lesson that can be applied to the applications you create in the future.
Skills Achieved in Lesson 2
You achieved the following skills and knowledge in Lesson 2:
When establishing communications for your application, two key tags are required: a port tag to represent the port of the PC to which the I/O device is connected, and an I/O device driver tag to communicate (using appropriate protocols) with the I/O device to which the system equipment is attached;
Your application can support multiple I/O device driver tags and multiple port tags. More than one I/O device tag can be connected to a single port, and more than one serial port tag can be established according to the number of ports your PC has available;
The Tag Browser is the VTS tool by which you add, modify, and manage tags;
When a tag type is selected from the Types drop-down list of the Tag Browser, the tag list is filtered to display only those tags belonging to the selected type;
The tag type selected in the Types drop-down list determines the type of tag that will be created when the New button is clicked;
When entering values into the fields of tag properties folders (or any other dialog), always remember to press the Enter key on your keyboard to set the value in the field;
VTS automatically configures the correct properties for the settings of a serial port tag, based on the available serial port(s) of your PC;
You need to know about the physical I/O device that is reading and writing data in order to correctly select an I/O driver tag and establish its properties;
All standard tag types have the same four initial properties; these are, "Name", "Area", "Description", and "Help Search Key";
The Area property of a tag properties folder displays the last known entry (for example, if you entered "Station 1" in the Area field for the last tag you created, the next tag you create will have "Station 1" automatically entered in its Area field;
It is recommended that you use the Area drop-down list to select an existing area for your tags, rather than retyping the area each time. Doing so will help to avoid mistyping areas;
The tag properties folders for a tag consist of a series of properties common to the standard tag type to which the tag belongs. These properties are organized by topic, with sets of properties appearing on appropriately labeled tabs of the tag properties folder; and
Not all properties that appear in a tag properties folder are necessarily required for that tag to function properly.