SignedAlarmAck() runtime behavior

At runtime, the SignedAlarmAck() function does the following:

1. The function checks whether a signature is required on the alarms to be acknowledged.

   1. It checks if the parameter Signature_Reqd_for_Range is true.

   2. If so, it checks if security is enabled on your HMI/SCADA project or application.

   3. If so, it checks the Priority for each designated alarm and compares it against the indicated priority range. If any of the designated alarms falls within the priority range, a signature is required.

   4. If none of the designated alarms falls within the priority range, but no one is logged in, a signature is required.

   5. If no alarm is waiting for an acknowledgement, the function will do nothing, but will return a value indicating that no alarms are waiting for acknowledgement.

2. If none of the indicated alarms requires a signature, the function displays a simple pop-up acknowledgement dialog.

   6. When the user clicks OK, the function writes the acknowledgement comment to the AckMsg attribute of each of the alarms identified in the Alarm_List parameter.

      The system identifies the logged-on user, if any, as the one who acknowledged all of the alarms.

   7. If the user has permission to acknowledged alarms, or the project or application is unsecured, the alarms are marked as having been acknowledged.

   8. If the acknowledgement fails, there is no direct feedback to the user. The status of the alarms, however, will show that they have not been acknowledged.

3. If any of the indicated alarms requires a signature and is waiting for an acknowledgement, the function displays a pop-up acknowledgement dialog that requires a signature.

   9. This dialog has edit fields for the user's credentials: name, password, and domain. By default, the user displayed is the logged-in user, if any. Otherwise, it is blank. All of these fields can be edited.

      If Smart Cards are not enabled, the mode buttons for selecting Smart Card or password authentication are disabled.

   10. The user enters the acknowledgement comment, if enabled, and the user’s credentials.

   11. The function validates the user's credentials.

   12. If the user credentials are invalid the function displays an error message.

       When the user clicks OK on the error message, the function re-displays the alarm authentication dialog, and allows the user to try again.

       When the dialog is redisplayed, it shows the same user's name, domain, and acknowledgement comment as were entered, but the password or Smart Card PIN field is blank. The user may then re-try the authentication or cancel.

   13. If the user credentials are valid, the function writes the acknowledgement comment to the AckMsg attribute of each of the alarms identified in the Alarm_List parameter.

       The system identifies the authorizing user as the one who acknowledged all of the alarms, including those that don't require a signature.

       If the user has permission to acknowledgement alarms, the alarms are marked as having been acknowledged.

       If the acknowledgement fails, there is no direct feedback to the user. The status of the alarms, however, will show that they have not been acknowledged.

4. The function provides a return value, and writes an information message in the Logger if an error occurs or the operation is canceled.

For information on run-time behavior and the sequence of executing script operations, see SignedWrite() Script Execution Sequence at Run Time.