Delayed Notification Functions; Communication Functions With Derived Jobs - Siemens SIMATIC S7-400H Manual

If a master/standby switch-over has been performed then in the next cycle after
the update OB 1 has its own identifier (see Reference Manual System Software for
S7-300/400, System and Standard Functions). For other peculiarities when the
configuration is changed see Section 6.2.3.

Delayed notification functions

The SFCs, SFBs and operating system services listed trigger messages to all the
parameters logged on in each case. These functions are delayed after the start of
the update.
• SFC 17 "ALARM_SQ", SFC 18 "ALARM_S", SFC 107 "ALARM_DQ", SFC 108
"ALARM_D"
• SFC 52 "WR_USMSG"
• SFB 31 "NOTIFY_8P", SFB 33 "ALARM", SFB 34 "ALARM_8", SFB 35
"ALARM_8P", SFB 36 "NOTIFY", SFB 37 "AR_SEND"
• Statuses
• System diagnostics messages
From this time on instructions to block and release events via the SFC 9
"EN_MSG" and the SFC 10 "DIS_MSG" will be rejected with a negative return
value.

Communication functions with derived jobs

If a CPU receives one of the jobs listed below it must in turn generate
communication jobs from this and send these to other modules. This could be,
for example, instructions to read or write parameter data records from/to modules
of the remote input/output station. These jobs will be rejected until the update is
complete.
• Read/write data records via O & M functions
• Read data records via SSL information
• Block and release messages
• Log on and off for messages
• Acknowledge messages
Note
The last 3 functions are recorded by a WinCC system and automatically repeated
when the update is complete.
Automation System S7-400H Fault-tolerant Systems
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Linking and Synchronizing
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