Siemens SINUMERIK 802C User Manual

Start-Up
4.3 Starting up the PLC
4-52
SINUMERIK 802C
6FC5 597–3AA20–0BP2 (01.02)
Example:
S Hardware start–up switch position 3
S Restart from operator panel
=> Restart is active from next power–up of the control system
The Run mode activates the cyclic mode.
In the Stop mode, the following actions are initiated:
S All hardware outputs are disabled.
S The NC Ready relay is inactive.
S No cyclic operation (active user program is not executed)
S Process image is no longer updated (”frozen”)
S Emergency Stop active
The user can also use the PLC 802 Programming Tool to start the Stop or Run modes.
A corrected or new project can only be loaded into the control system in the Stop mode. The
user program comes only into effect with next power–up or when the Run mode is active.
4.3.3 PLC alarms
The control system displays a maximum of 8 PLC alarms (system alarms or user alarms).
The PLC manages the alarm information per PLC cycle. It stores or deletes the alarms in the
alarm list according to their occurrence. The first alarm in the list is generally the alarm last
occurred.
If more than 8 alarms occur, the first seven alarms occured are displayed, and the last one
with the highest cancel priority is displayed.
Alarm response and cancel criterion
Furthermore, the PLC manages the alarm responses. The alarm responses are always active,
irrespective of the number of active alarms. Depending on the type of the alarm response, the
PLC triggers an appropriate response.
Each alarm requires a cancel criterion to be defined. The PLC uses the SELF– CLEARING
criterion as default criterion.
Cancel criteria are:
S POWERONCLEAR: The alarm is canceled by switching off/switching on the control sy-
stem.
S CANCELCLEAR: The alarm is canceled by pressing the Cancel key or the Reset key
(analogously to NCK alarms).
S SELF–CLEARING: The alarm is cleared because the cause resulting in the alarm has
been eliminated or does not exist any longer.
Desired alarm responses are defined for each alarm in the PLC. By default, the PLC uses the
SHOWALARM response (bit0 – bit5 = 0).

Siemens SINUMERIK 802C Specifications

General

Brand	Siemens
Model	SINUMERIK 802C
Category	Control Systems
Language	English