Creating HMI data
Just as with control data, it's usually a good idea to have a general concept of how human-machine interface (HMI) data will come together.
This is the information that is used to display statuses, control graphics, and any other specific HMI requirements. Segregating these variables from other variables helps keep the vast amount of data that HMI/supervisory control and data acquisition (SCADA) systems require clean and easy to use.
Creating a UDT to house this information makes it easy to add it into datasets for assets later on, as illustrated in the following screenshot:
Figure 6.24 – Example of HMI data for a pump asset
Each instance of a pump asset would then have its own UDT_Pump_HMI_Data instance that the HMI would interact with.
This approach, much the same as for control data, allows for each standard control object in the project to have a known and designated area for HMI interaction. This helps unrelated blocks...