Developed a flow totalizer logic in TIA Portal using OB30 for precise time-based integration.
The analog input from the flow transmitter is first processed through Norm_X → Scale_X to obtain the flow rate, which is then converted from m³/h to m³/s and accumulated during each OB30 cycle. The accumulated total is transferred from a static variable to an output tag for HMI display.
A MUL instruction (×0) is used to reset the totalizer when required.
Watching the totalizer value increase steadily on the HMI was a rewarding validation of correct scaling, integration, and timing.
Author: Emmanuel Fabiyi