Sending and receiving signaling patterns

This topic describes how to:

Query the current state of the supervisory signaling bits.
Assert a supervisory signaling pattern at a station.

These functions are not intended for use in typical applications. Ordinarily, the supervisory signaling is transparently controlled by the on-board DSP. Use these functions when special-purpose applications require explicit control of the supervisory signaling. In such cases, disable enhanced mode as described in CX 2000 modes.

Querying signaling bits

To retrieve the current state of the supervisory signaling bits for a station, invoke cdiGetSignalState, passing the context handle to the station. cdiGetSignalState returns a pointer to a value indicating the state of the bits:

Pattern Value	Description
00000xxx (xxx is any value)	The bits are low (the station is on-hook).
00001xxx (xxx is any value)	The bits are high (the station is off-hook).

Do not use cdiGetSignalState when enhanced mode is enabled.

Asserting a signaling pattern at a station

To assert a signaling pattern at a station, invoke cdiAssertSignal. With the invocation, pass the context handle to the station and one of the following values:

Pattern value	Description
0x00	Battery off, no ringing
0x08	Battery on, no ringing
0x0C	Battery on, continuous ringing

Do not use cdiAssertSignal when enhanced mode is enabled.