Polycom SoundStructure C16 Design Manual page 391

Description
This parameter indicates the ringing state for the telephony interface. While
the telephony interface is ringing, reading this parameter will return 1. When
the telephony interface is not ringing, reading this parameter will return 0.
Acknowledgements for this parameter will be automatically sent whenever
this parameter changes state due to a hook flash, auto-answer, or
auto-hangup.
Examples
Command
val phone_ring
"Phone In" 1
phone_ring_tone_en Enable Ring Tones For Telephony Interface
Description
This parameter enables or disables ring tone generation for the telephony
interface. If ring tones are enabled (1), then a ring tone is played whenever
there is an incoming ring signal on the telephony interface.
phone_tone_gain Telephony Input Tone Gain
Response
Argument Argument value
Channel Type Virtual Channel
Value Type Boolean
Read/Write Mode Read/Write
Phys Chans Analog Telephony Input
Virt Chans Mono
Default 1
Argument Argument value
Channel Type Virtual Channel
Value Type Floating-Point
Read/Write Mode Read/Write
Phys Chans Analog Telephony Input
Description
Returns the value 1 when the incoming phone
line associated with the virtual channel "Phone
In" is ringing. Note that the phone in virtual
channel name must be used, not the phone out
virtual channel name.
Command Protocol Reference Guide
A - 49