This training video is Part 2 of the HMIWorks C-programming series and walks through building a multi-device Modbus RTU monitoring and control project on an ICP DAS USA TouchPad. It explains how to create serial connections and user-defined Modbus devices in HMIWorks, define tags and virtual tags, and use C functions to continuously poll multiple slave devices—even when the HMI is on different screens. The demo shows how to implement limit checking on analog inputs, automatically drive analog and digital outputs based on low/high alarm thresholds, and display controller/alarm/communication status using object lists, checkboxes, timers, and multi-page navigation. Finally, the project is tested with a Modbus simulator to validate real-time updates, alarm behavior, and communication loss handling before deploying to live devices.
