In order to modify the properties of a TAC or a TAC queue, you must call KC_MODIFY_OBJECT with the object type KC_TAC.
It is not possible to change the status of a TAC and at the same time reset specific statistical values.
Changes to the status of a TAC or a TAC queue take effect immediately and continue to apply beyond the end of the application run. Changes to the statistical values of a transaction code take effect immediately.
If you want to control accesses to a transaction code by means of a key set, you can assign an existing key set to the access list of the transaction code. If there is a lock code, you have to remove it (set it to zero). Conversely, if access to the transaction code is protected by a lock code, there must not be a key set defined in the access list.
You can also protect a TAC queue against unauthorized reading/deletion and writing by means of a key set. To do this, assign the desired key set to the q_read_acl and/or q_write_acl parameters.
Changes to the parameters that control access continue to apply after transaction processing beyond the end of the application run.
Backup of messages in the dead letter queue in the event of processing errors can be enabled or disabled for asynchronous transaction codes using CALL=BOTH/FIRST and TAC queues. This backup option is not possible for MSGTAC and KDCDLETQ. Enabling and disabling of backup to the dead letter queue remains in effect after the end of the transaction and beyond the application run.