Siemens simatic hmi op27 Equipment Manual page 58

Figure 6-1
Event message window:
The event message window must be selected and then deselected by the opera-
tor. If an event message is not currently waiting, the standby message is dis-
played.
Close the event message window by pressing this function key a second time.
Message archive Alarm and event messages are written in the OP message archive when they
arrive. The message archive is a buffer in which all message events are entered
in chronological order. Message events consist of:
S
S
S
The message archive is implemented as a FIFO buffer. When the buffer is full,
the oldest messages are deleted.
Overflow warning
During configuration, it is possible to define a remainder buffer size for the
message archive. As soon as this remaining buffer capacity is reached, the OP
automatically issues an overflow warning (system message). Messages con-
tinue to be entered in the message archive even after the remaining buffer
capacity has been reached.
Message bit If the conditions for issuing a message have been fulfilled in the process cur-
procedure
rently running, e.g. a value has been reached, a bit is set in the data area by the
PLC application program for an event or alarm message. The OP reads the data
area after a configured polling time. In this way, a message is detected as hav-
ing "arrived". The bit is reset by the PLC when the condition for issuing the
message no longer exists. The message is then regarded as having "departed".
OP27, OP37 Equipment Manual
Release 05/99
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Message number
Time
0000048 11:34:02
Boiler 25: Temperature 156 degrees
Summon Shift Engineer. Tel.: 9456
Alarm message window (example)
Activate the event message window by pressing the function key
assigned to the icon depicted on the right in the Message Process-
ing standard screen.
arrival of a message
acknowledgment of an alarm message
departure of a message.
Number of unacknowledged
Date
Acknowledgment group
27.03.97 QGR 01
Process value
Messages
messages
2
6-5