Panasonic KX-TD500 System Reference Manual page 742

3.07 Busy Station Signaling (BSS)
Description
When the called extension user is busy talking on
a DN or CO button, and the DN button is idle,
Intercom-Busy Station Signaling informs the
other extension user that he or she is called by
another extension with the flashing DN button.
The called extension user's telephone must be
off-hook.
To activate this function, assign "System-Class of
Service", BSS/OHCA to "Yes".
Programming
System Programming
"System-Class of Service (1/3)",
BSS/OHCA
Conditions
Intercom-Busy Station Signaling is effective if the
called extension is preset to either of the
following functions:
• "System-Class of Service", BSS/OHCA
Deny is set to "Yes".
• "System-Class of Service", Call Forwarding/
Do Not Disturb is set to "Yes".
Operation
Calling an extension
1. Press an idle LOOP key.
LOOP
• The SRC indicator lights and
dial tone sounds.
2. Dial the directory number of the
other extension.
• You hear busy tone.
3. Dial " 3 ".
• You hear ringback tone.
Reference
VT Dumb
10-D-4.01 11-C-7.00
6-D-14