TCAS must have an entry in the MVS™ program properties table (PPT). This entry designates the execution attributes of TCAS, which should be as follows:

• The program cannot be canceled.
• Unique protection key 6 must be assigned to the program.
• The program is privileged and is not swapped unless the address space is in a long wait.
• The program is a system task and is not timed.
• There is no host affinity.