Data Exchange between VTS and a Communication Driver

VTS uses I/O tags that are assigned to read from or write to specific address in the PLC or RTU. These include analog input and output tags, digital input and output tags, status tags, control tags, etc.

All I/O tags have the following two properties in common:

•      I/O Device: The "I/O Device" property tells the tag which driver tag it should use in order to communicate with the correct PLC or RTU.

•      Address: The "Address" property tells the tag which memory location at the PLC or RTU to read from or write to.

All communication drivers have a common property:

•      Port: The "Port" property indicates to the device driver tag the correct serial port or TCP/IP socket that it should use to transmit and receive data from the PLC or RTU.

In summary, port tags provide communication over a physical connection between remote equipment and the PC. Communication drivers read and write data over that connection using the protocol required by the remote device. I/O tags within VTS read data from or send data to the communication drivers in order to complete the link between the specific addresses in the remote equipment and the drawing methods on the screen of a VTS application.