Plc Alarms - Siemens Sinumerik 802D sl Instruction Manual

Starting Up the PLC
11.3

PLC alarms

11.3 PLC alarms
The control system displays max. 8 PLC alarms (system alarms or user alarms).
The PLC manages the alarm information per PLC cycle. It saves/cancels the alarms accor-
ding to their times of occurrence. The first alarm in the list is always the alarm last occurred.
If more than 8 alarms have occurred, the first seven alarms and the newest alarm with the
highest cancel priority are displayed.
Alarm response and cancel criteria
In addition, the alarm responses are managed by the PLC. The alarm responses always
come into effect, irrespective of the number of active alarms. Depending on the type of the
alarm response, the PLC will trigger the required action.
A cancel criterion must be defined for each alarm. The PLC uses the cancel criterion SELF-
CLEARING by default (see "Configuring user alarms").
Cancel criteria are:
S POWERONCLEAR: The alarm is canceled by turning off/turning on the control system
(POWER ON).
S CANCELCLEAR: The alarm is canceled by pressing the Cancel key or the Reset key
(analogously to the NCK alarms).
S SELF-CLEARING: The alarm is canceled, since the alarm cause is no longer present.
The cancel conditions have the following priority:
S POWERON CLEAR – system alarms (highest priority)
S CANCEL CLEAR – system alarms
S SELF–CLEARING – system alarms
S POWERON CLEAR – user alarms
S CANCEL CLEAR – user alarms
S SELF-CLEARING – user alarm (lowest priority)
The responses to be triggered by the alarm in question in the PLC are defined for each
alarm. The PLC uses the alarm response SHOWALARM by default.
Alarm responses are:
S PLC stop: The user program is not executed any more, Profibus DP is inactive, and the
hardware outputs are disabled.
S EMERGENCY STOP: Once the user program is executed, the PLC transmits the EMER-
GENCY STOP signal to the NCK via the user interface.
S Feed disable: Once the user program is executed, the PLC transmits the feed disable
signal to the NCK via the user interface.
S Read-in disable: Once the user program is executed, the PLC transmits the read-in disa-
ble signal to the NCK via the user interface.
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SINUMERIK 802D sl Instruction Manual (BA), 05/2005 Edition
6FC5 397-0CP10-1BA0