8 Safety-related Aspects of the User Program HIMatrix
Page 52 of 72 HI 800 023 E Rev. 1.01
Global variables can be assigned to these system variables; the value of the global
variables is modified using a physical input or the user program logic.
Example: A key switch is connected to a digital input. The digital input is assigned to a
global variable associated with the system variable Read only in Run. The owner of a key
can thus activate or deactivate the operating actions 'stop', 'start' and 'download'.
8.2.3 Locking and Unlocking the Controller
Locking the controller locks all functions and prevents users from accessing them during
operation. This also protects against manipulations to the user program. The scope of the
locking procedure should be viewed relative to the safety requirements for using the PES,
but might also be coordinated with the test authority responsible for the final system
acceptance test.
Unlocking the controller deactivates any locks previously set (e.g., to perform work on the
controller).
i
The locking and unlocking functions are only available with controllers and the
F3 DIO 20/8 01 remote I/O, but not with the remaining remote I/Os!
Versions beyond 7
Three system variables serve for locking:
Variable Function
Read only in Run ON: Starting, stopping, and downloading the controller are locked.
OFF: Starting, stopping, and downloading the controller are possible.
Reload Deactiva-
tion
ON: Reload is locked.
OFF: Reload is possible.
Force Deactiva-
tion
ON: Forcing is deactivated.
OFF: Forcing is possible.
Table 30: System Variables for Locking and Unlocking the PES
If all three system variables are ON: no access to the controller is possible. In this case, the
controller can only adopt the STOP/VALID CONFIGURATION state after a restart. Then
loading a new user program is possible.
Example for using these system variables:
To make a controller lockable
1 Define a global variable of type BOOL and set its initial value to OFF.
2 Assign global variables to the three system variables Read only in Run,
Reload Deactivation, and Force Deactivation.
3. Assign the global variable to the channel value of a digital input.
4. Connect a key switch to the digital input.
5. Compile the program, load it on the controller, and start it.
The owner of a corresponding key is able to lock and unlock the controller. In case of a fault
of the corresponding digital input device or input module, the controller is unlocked
Versions Prior to 7
Locking procedure - Proceed as follows to lock the PES:
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