Panasonic KX-TD500 System Reference Manual page 237

(Example 2) O1S → H → 4T → 2T → O2S → H
→ TR
If "H" command is used as shown
above, Music on Hold is always
sent to the caller whether OGMs
are In Service or not.
(Example 3) O1S → 2T → O2W → OFF
(1) (2)
UCD Group
(1) The caller hears OGM1.
(Example)
Sorry, all lines are busy.
Please wait a moment.
If OGM1 is busy or Out of Service,
this step will be skipped.
Then the caller hears ringback tone.
(2) The caller hears Music on Hold for
30 seconds (2T).
(3) The caller hears OGM2.
(Example)
Sorry, all lines are still busy.
Please call us again.
Thank you for calling.
If OGM2 is busy, the caller first
hears ringback tone and then will
hear OGM2 as soon as it becomes
available.
(4) The caller is disconnected from the
switch.
(Example 4) H → TR
(1)
UCD Group
(1) The caller hears Music on Hold until
the Overflow destination becomes
idle.
(3) (4)
3-D-19
(Example 5) H → O1S → TR
(1) (2)
UCD Group
(1) This step is skipped automatically.
"H" does not function.
(2) The caller hears OGM1 followed by
Music on Hold.
(3) The caller is transferred to the
Overflow destination.
(Example 6) → O1S → 2T → O2W → 2T → RET
(1)
(1) The caller hears OGM1.
(Example)
Sorry, all lines are busy.
Please wait a moment.
If OGM1 is busy or Out of Service,
this step will be skipped.
Then the caller hears ringback tone.
(2) The caller hears Music on Hold for
30 seconds (2T).
(3) The caller hears OGM2.
(Example)
Sorry, all lines are still busy.
Please wait a moment.
If OGM2 is busy, the caller first hears
ringback tone and then will hear
OGM2 as soon as it becomes
available.
(4) Same as the step (2).
(5) The caller hears Music on Hold for
15 seconds and go back to the step
(1).
(3)
(2) (3) (4) (5)