Abstract: A time-division switching system including first and second control units operating in accordance with a generic program is disclosed. After a new generic program is stored in the second control unit, the first control unit still operating in response to the old generic program initiates the performance of a test sequence by the second control unit. The first control unit times the execution of the test sequence. When the test sequence is not completed within a predetermined period of time or when test results generated by the test sequence do not match expected test results, a failure message is generated. Alternatively, when the test sequence is completed within the predetermined period of time and test results match the expected test results, a success message is generated.

Abstract: In a multiprocessing system, a method of efficiently maintaining a program process active while also ensuring that the process is deactivated when no longer needed. One or more subordinate processes are linked to a controlling process. Each subordinate process has an associated overall timer. As long as the controlling process keeps sending periodic keep-alive messages to a subordinate process, the associated overall timer is prevented from timing out. When the controlling process stops sending keep-alive messages, the associated overall timer times out and the subordinate process is deactivated.