Siemens SIMATIC ET 200AL - Page 662

Alarms
6.1 Creating alarms with the "Program_Alarm" instruction
Diagnostics
Function Manual, 09/2016, A5E03735838-AD
77
Note
The "Program_Alarm" instruction can only be called in a function block.
A program alarm can be up to 256 bytes long in total (with associated values and texts from
the text list).
The associated values can be a maximum of 512 bytes in leng
th. Text lists are not affected
by this.
The CPUs of the SIMATIC S7
-1500 product series have the following memory for text lists:
•
CPU 1510-x to CPU 1513-x: 2.25 MB
•
CPU 1515-x to CPU 1516-x: 4.5 MB
•
CPU 1517-x to CPU 1518-x: 6.75 MB
The number of configurabl
e program alarms depends on the CPU used. With a
CPU 1515
-2 PN, for example, a maximum of 10,000 program alarms are possible. You can
find this information in the device manual for the respective CPU under "Number of
configurable alarms".
The number of sim
ultaneously active "Program_Alarms" depends on the CPU used. With a
1515
-2 PN CPU, for example, a maximum of 600 program alarms are possible. You can find
this information in the device manual for the respective CPU under "Number of reserved user
interrupt
s".
Sometimes, it is not possible for all program alarms that are active at the same time to be
output within one cycle. Query the status of each "Program_Alarm" and activate the
instruction again, if necessary. The cycle time is increased for a short time
by simultaneously
activating/sending multiple "Program_Alarms".
A maximum of 40,000 program alarms should be configured in a STEP 7 project on a 64
-bit
operating system.
Additional information
You can find more information on creating program alarms in the STEP 7 online help under
"Creating and editing alarms".