The CTCSS Encoder has a number of modes from OFF to Timed. The modes allow it to be controlled by the transmitter PTT or the enabled paths. Two configuration settings are required for this solution to work.
Set the CTCSS Encoder Mode to 4. This turns on CTCSS when a path to a transmitter goes active and starts the CTCSS on timer when the path goes inactive. Because this mode is only triggered when a path is active, an ID will not turn on the CTCSS. Nor will any other announcement.
Set the CTCSS ON Time to how long you want the repeater to be idle before you want the final ID to be generated with no ID message. I chose a minute in the example below.
; set TX1 CTCSS Encoder Mode 4 MPW 02 1 4 0 * ; set 60 seconds MPW 09 0115 6000 *