Panasonic KX-NS500 Pc Programming Manual page 228

9.2.4 PBX Configuration—[1-1] Configuration—Slot—System Property—NSVM
Maximum Cyclic Tone Time
Specifies the length of time of a continuing cyclic tone that the PBX will detect as the end of a call.
Value Range
1000–60000 (ms)
Maintenance Console Location
9.2.4 PBX Configuration—[1-1] Configuration—Slot—System Property—NSVM
228 PC Programming Manual