This example is a continuous loop.
If you want a certain number of DISA repeat (for example three) record the same message 501,502 and 503.
OGM number 1 - 501 / 1 Digit AA Destination -Dial 0 - 502
OGM number 2 - 502 / 1 Digit AA Destination -Dial 0 - 503
OGM number 3 - 503 / 1 Digit AA Destination -Dial 0 - 302 ( for disconnecting caller)
302 is a digital phone that is not connected ( DXDP or any free digital port ),it is also usable Modem nummber 599 od ISDN remote nummber 699.
Panasonic is constantly upgrading PBX features and there are many new instructions, but basic documents are Instalation,Feature,Programming,User Guide
TVA / TVM is a good device but I never full learned it.
UM is full features TVM50 ( 2 channel) device inside the NS PBX.