Teco_ModemComm is a project designed to demonstrate how to make a connection to the Teco PLC via a modem connected to the computer's serial port. Within the System device, several tags of type Word are defined to monitor and control the state of the modem and the PLC device. The Modem1Control tag is used to control Modem1 – it connects the Combo Box component placed in the visualization window and the Modem1 object defined via the Project Structure Manager (on the Basic page, the Control property must be active and the tag specified). The Tecomat1Control tag is used to control Tecomat1 (allows selecting one of the following commands: Disconnect, Connect, 'Connect, read data and disconnect') – it connects the Combo Box component placed in the visualization window and the Channel1 object defined via the Project Structure Manager. The Tecomat1Status tag, which is also connected to the Channel1 object, is processed in the Tecomat1StatusChanged script and the result is shown in the visualization window. The Tecomat1Status tag is linked to the Status property via the Project Structure Manager (Tecomat1 > Channel1 > Advanced). Similar tags exist for Modem2 and Tecomat2. Also, the Tecomat1 and Tecomat2 devices and the required tags are defined via the Device Manager.

Through the Project Structure Manager, the Channel type of the Tecomat1 device is set to Dial-up (modem), the required Phone number is specified, and the Tecomat1Control and Tecomat1Status tags are connected on the Advanced page. In the Modems folder, the Modem1 object is defined and the Modem1Control tag is connected to the Control property of this object. The Tecomat1StatusChanged script is defined via the Script Manager. The script uses bit masking to extract information about the Tecomat1 device's state from the Tecomat1Status tag. Similar objects are defined for the Tecomat2 device.