TCO components

TCO (time-controlled operations) allows you to initiate time-driven procedures for any IMS operation. TCOs consist of many components and at least one exit routine.

TCO consists of:

• An initialization routine that performs initial housekeeping and starts the TCO timer service
• A TCO timer service that processes startup requests and timer requests, calls an exit routine, and waits for future requests
• A device-dependent module that passes the input generated by the timer service to the IMS control region
• An offline script-member verification utility that ensures that IMS only processes error-free scripts
• A termination routine that performs cleanup and tells the timer service when to terminate

You also need an exit routine. This can be the exit routine IMS provides or an exit routine you write.

TCO and the exit routines execute as a subtask of the IMS control region. An error in the exit routine terminates TCO only, and does not disrupt IMS online operation.