HMI Alarming
PLCnext Engineer allows you to configure an alarming system. The alarming system provides a tool for notifying the operator about alarms originated in the alarm source (for example, protocol, application program, PLCnext component). Alarms are used to display warning messages informing the operator about faulty or abnormal conditions and deviations, or status changes in the alarm source that could cause problems and require the response of the operator. Whenever the value of, for example a variable, exceeds a threshold value or a pattern of a digital signal matches a preconfigured pattern, an alarm becomes active and a message is displayed during process operation to notify the operator of a problem.
In PLCnext Engineer, the definition of alarms and their properties is done using the 'Alarm Server | Alarms' PLANT editor. The editor allows you to select the signal (application variable or port) to be monitored, the type of alarm (for example, bit pattern alarm, boolean alarm etc.), the alarm condition, etc. (see the topic "Alarming" for details).
The alarms generated from the alarm source can be visualized in the HMI application. The alarm configuration and information queried from the alarm source and the alarm data at runtime are stored in an alarm array. By binding the elements of the alarm array to HMI symbol parameters, the alarms can be made visible and allow interaction such as alarm acknowledgment and confirmation.
This chapter provides information about the following topics: