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Entry type: FAQ, Entry ID: 6691096, Entry date: 09/08/2005

Which process control group messages are created in the OS?

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Configuration Notes:
With STEP 7 V5.1 there is a new structure and different behavior of the group messages for the HMI systems. Previously there were seven group messages. There are now 21 group messages in the new version. The seven original messages are contained in three groups of seven. The following table lists the new messages.



AS fault synchronous incoming
AS fault asynchronous incoming
Module fault incoming
Stop/abort fault incoming
H/F system fault incoming
Communications fault incoming
Fault in CP/FM module incoming

Group 1

AS fault synchronous outgoing
AS fault asynchronous outgoing
Module fault outgoing
Stop/abort fault outgoing
H/F system fault outgoing
Communications fault outgoing
Fault in CP/FM module outgoing

Group 2

Message about AS fault synchronous
Message about AS fault asynchronous
Message from module
Stop/abort message
H/F system message
Communications message
Message from CP/FM module

Group 3

The three groups always contain the same messages for the different status options of the message (incoming, outgoing, status unknown).
Because of the properties of the message class "OS Instrumentation and Control Message" the IC messages do not have an "incoming/outgoing" display in the message line. Therefore an extra "incoming" and the "outgoing" message is sent for each individual message.
The message of the type "outgoing" is however only displayed when the message of the type "incoming" has also been acknowledged beforehand. If not, then the message is not displayed again.

Group 3 is needed, because after an update of the message picture or WinCC ON/OFF (struck-out message), a status is no longer available. With this type of message supplementary values are transferred with the event ID and these values contain the status information. Since the message is always of the type "incoming" here, it can only be indicated that a message of this type was here. The user must then look in the diagnostics buffer of the CPU himself to find out the reason for the message.

Below is the assignment of the organization blocks in STEP 7 to the individual group messages. This list does not presume to be complete. It is rather an indication of the possible causes. The user has to find the associated detailed information in the diagnostics buffer of the CPU based on the time stamp of the message concerned.


Detailed information in the CPU

AS fault synchronous

OB121, OB122

AS fault asynchronous

All OB8x

Module fault

OB82, OB83, OB86

Stop/abort fault

Stop and abort events direct

H/F system fault

OB71, OB72

Communications fault


Fault in CP/FM module

CPs and FMs direct to WinCC

BPC, Basic Process Control, Wizard, IC message

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