Siemens SIMATIC ET 200AL, System Manual

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Diagnostics
76
Function Manual, 11/2019, A5E03735838-AF
Alarms
6
Introduction
Alarms allow you to display events from processing in the automation system and to quickly
detect errors, to precisely localize them and to remove them. Downtimes are significantly
reduced in a plant.
Before alarms can be output, they need to be configured.
You can create, edit and compile event-dependent alarms along with their alarm texts and
alarm attributes and display them on display devices.
In STEP 7, you create program alarms in the user program with the "Program_Alarm"
instruction. You edit the attributes and alarm texts in the alarm editor in STEP 7.
You can output the alarm status with the "Get_AlarmState" instruction.
Advantages of program alarms
Compared to other alarm methods, such as HMI discrete alarms, program alarms offer the
following advantages:
● Central engineering in STEP 7: You only configure a program alarm once for the CPU.
The program alarm is automatically transferred from the CPU to all registered HMI
devices.
● System-supported acknowledgment: The acknowledgment of a program alarm on an HMI
device is automatically updated on other HMI devices by the CPU.
● Time stamping close to the event in the CPU
● Identical time stamps of the alarms on multiple HMI devices without time synchronization