Exit protocol

The scrambling exit is called during a copy operation with an input and output template, and where the output field has been defined with Scramble Type 4 ("Exit") and mapped to an input field. The exit is called in these situations:
Initialization
The first call to the exit for each field is an initialization call that causes the exit to perform set-up procedures. A 1024-byte user area is provided, in addition to the user constant for the exit to use.
Scramble
This call is repeated for each instance of the field being copied. On this call, the exit is expected to provide File Manager with the scrambled output value for the field, or a directive for File Manager to scramble the field.
Termination
The last call for each field is a termination call that causes the exit to perform clean-up procedures.