The Variable Unlocker node is designed to be used in conjunction with password protected Global Variables.
If a Global Variable has been password protected it is impossible to read or reference it within a Task - attempts to do so will result in an exception. The Variable Unlocker allows you to tell Presence the password to unlock the variable before attempting to read it.
The following is an example of what a Task looks like with a Variable Unlocker node:
In the above example the LDAP Query can now successfully reference a password-protected Global Variable (assuming the correct password was entered).
After dragging a Variable Unlocker into your Task you will be prompted to enter the password:
This password will be used to unlock any subsequent password-protected variables. Therefore if you have used different passwords for different variables and need to reference them in the same Task you will need to insert a Variable Unlocker before each one. For this reason it can be a good idea to use a consistent password for variables that are likely to be used in the same Tasks.
The password is stored in encrypted form, making it difficult for anyone to establish what the password is after entering it.