Siemens simatic hmi op7 User Manual

7-12
Equipment Manual OP7, OP17
Release 04/99
7.4 Deleting Messages
All message events for event and alarm messages are automatically stored in
the event message buf fer or alarm message buffer respectively . Each of these
buf fers has space for up to 256 events. T o prevent a buf fer overflow , event
and alarm messages must be deleted from their buf fers.
Message events from the event message buf fer or alarm message buf fer are
deleted
 automatically when buf fer overflow occurs
 by means of the appropriate standard screen.
System messages are deleted automatically only when the buf fer overflows.
7.4.1 Deleting alarm message and event message buffers upon buffer
overflow
When the specified remaining buffer capacity for the alarm and event mes -
sage buf fers is reached, an overflow warning is output by default. Output of
this overflow warning can be activated and deactivated online via the corre -
sponding standard screen:
 Alarms  Overflow
 Events  Overflow
If the alarm or event message buf fer has insuf ficient space to accept any
more message events, message events are automatically deleted until the spe -
cified remaining buf fer capacity is reached. Deletion is carried out in the fol -
lowing order:
 The oldest departed messages.
For departed event messages, the message events ’arrival’ and ’departure’
are deleted. For departed alarm messages, the message events ’arrival’,
departure’ and ’acknowledged’ are deleted.
 Queued messages.
If there is still insuf ficient space for new events, the oldest queued mes -
sages are deleted in the case of event messages.
In the case of alarm messages, deletion is carried out in the following or -
der:
 Acknowledged alarm messages yet to depart
 Unacknowledged alarm messages that have already departed
 Unacknowledged alarm messages yet to depart.
If “Printout Overflow” has been configured and a printer is connected to the
OP and switched on, a forced printout of all deleted messages is initiated.
Purpose
Overflow
warning
Deleting upon
buffer overflow
Automatic printout

Siemens simatic hmi op7 Specifications

General

Brand	Siemens
Model	simatic hmi op7
Category	Control Panel
Language	English