Siemens SIMATIC S7-400H System Manual page 151

Delayed message functions
The listed SFCs, SFBs and operating system services trigger the output of messages to all
logged-on partners. These functions are delayed after the start of the update:
● SFC 17 "ALARM_SQ", SFC 18 "ALARM_S", SFC 107 "ALARM_DQ", SFC 108
● SFC 52 "WR_USMSG"
● SFB 31 "NOTIFY_8P", SFB 33 "ALARM", SFB 34 "ALARM_8", SFB 35 "ALARM_8P",
● Process control alarms
● System diagnostics messages
From this time on, any requests to enable and disable messages by SFC 9 "EN_MSG" and
SFC 10 "DIS_MSG" are rejected with a negative return value.
Communication functions and resulting jobs
After it has received one of the jobs specified below, the CPU must in turn generate
communication jobs and output them to other modules. These include, for example, jobs for
reading or writing parameterization data records from/to distributed I/O modules. These jobs
are rejected until the update is completed.
● Reading/writing of data records using HMI functions
● Reading data records using SSL information
● Disabling and enabling messages
● Logon and logoff for messages
● Acknowledgement of messages
S7-400H
System Manual, 03/2012, A5E00267695-11
"ALARM_D"
SFB 36 "NOTIFY", SFB 37 "AR_SEND"
Note
The last three of the functions listed are registered by a WinCC system, and automatically
repeated when the update is completed.
Link-up and update
12.3 Link-up and update sequence
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