HIMax Safety Manual - Tuv-fs.com

9 Software HIMaxThe user only need to connect the PADT to the PES when loading the user program orperforming diagnostics. The PADT is not required during normal operation. Disconnectingthe PADT and PES during normal operation helps to prevent against unauthorized access.9.7 Locking and Unlocking the PES"Locking“ the PES locks all functions and prevents users from accessing them duringoperation. This also protects against unauthorized manipulations to the user program."Unlocking“ the PES: Deactivates any locks previously set (e.g., to perform work on thecontroller).Three system variables serve for locking:VariableRead only in RunReloaddeactivationForceDeactivationFunctionON: Starting, stopping, and downloading the controller are locked.OFF: Starting, stopping, and downloading the controller are possible.ON: Reload is locked.OFF: Reload is possible.ON: Forcing is deactivated.OFF: Forcing is possible.Table 15: System Variables for Locking and Unlocking the PESIf all three system variables are ON: no access to the controller is possible. In this case thecontroller can only be put into STOP state by restarting a processor module with the modeswitch in the Init position. Then loading a new user program is possible.Example for using these system variables:Make a controller lockable1 Define a global variable of type BOOL and set its initial value to FALSE.2 Assigne the global variable 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, lod 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 faultof the corresponding digital input module, the controller is unlocked.Page 52 of 70HI 801 003 D Rev.2.0