In WebHMI there is the concept of an alert. An alert is a state of the system that requires human attention. WebHMI signals all alert visually (red status bar on the dashboards) and an audible signal about unqualified accidents. Emergencies are logged for later analysis.
Usually alerts in the PLC are organized as a set of bits in any of the registers. Each bit is the flag of a single alert. In WebHMI alerts are configured in the register editor, i.e. a register or group of registers can be allocated for handling accidents. This makes it convenient to transfer them from the project to the project and from the connection to the connection when they are cloned. If any of the devices has a different format for representing the alert, for example, for each type of alert a separate register, or an alert code with a combination of a bit flag, etc. - such alerts can be brought to the standard way by using the capabilities of scripts on Lua, having generated the alert bits in the internal register.
Any of alerts can be allowed to be acknowledged. This allows you to tell the system that the operator is aware of its occurrence. Also for the alerts you can set its level - Information, Warning, Accident. In the initial state, the “Alerts” side menu item is empty, crashes there will only appear after creating at least one register with alert bits in the project.
When an alert occurs, the system will turn the status bar to red. The line will blink periodically to attract attention. Also, if there are unqualified alerts, an audible alert will be issued every 15 seconds.
To view the current alerts, you can click on the text with the alerts in the status line. This will open a pop-up window with a list of current crashes. In this window you can see their list, the time of the occurrence of the alert, acknowledge the alert, see the login of the user who acknowledged the alert.
Also, using Lua programs, you can perform certain actions depending on the current alerts. For example, you can send SMS messages if there are alerts that have not been acknowledged for more than 10 minutes. Or any other action. An example of handling an alert list is here
Past alerts can be viewed in the alert log.