27 m1x22_setringcadence, M1x22_setringcadence – Maxim Integrated 73M1822/73M1922 Modem API User Manual

Page 22

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73M1822/73M1922 Modem API User Guide

UG_1x22_055

22

Rev. 1.0

2.27 M1X22_SetRingCadence

Description

Set the ring cadence parameter for ring qualification process. The driver can be programmed to filter and
qualify incoming ring by discarding spurious signals that can be caused by line noises or distortions.
When set with these cadence parameters the driver will evaluate each incoming ring cycle based on
these parameters and emits M1X22_EVENT_QUALIFIED_RING event only when the ring cadence
matches at the specified number of cycles.

The ring cadence parameter consists of the frequency, cycle duration, period-1 “on”, period-1 “off”,
period-2 “on”, period-2 “off”, and number of cycles. This last parameter (number of cycle) is the number
of ring cycles matched before the ring is qualified. The sum of the period-1 “on”, period-1 “off”, period-2
“on” and period-2 “off” must be equal to the cycle duration parameter.

Remark

The system is defaulted to ring cadence screening disabled upon startup. Enabling or disabling the filter
using this API will not affect the behavior of the ring detection events (M1X22_EVENT_RING_START and
M1X22_EVENT_RING_END). The application may chose to ignore these two events if the qualified ring
event is preferred. To turn off this filter the same API can be used with the frequency or cycle duration
parameter equal ZERO.

Prototype

int M1X22_SetRingCadence (

M1X22_HANDLE channel,
unsigned int frequency,
unsigned int cycleDuration,
unsigned int periodOneOn,
unsigned int periodOneOff,
unsigned int periodTwoOn,
unsigned int periodTwoOff,
unsigned int numOfCycles );


Parameters

Data Type

Name

Description

M1X22_HANDLE channel

Channel handle obtained from open channel.

unsigned int frequency

Ring frequency to be detected.

unsigned int cycleDuration Duration of the cadence cycle (in milliseconds).

unsigned int periodOneOn

Period-1 “On” duration (in milliseconds).

unsigned int periodOneOff

Period-1 “Off” duration (in milliseconds).

unsigned int periodTwoOn

Period-2 “On” duration (in milliseconds).

unsigned int periodTwoOff

Period-2 “Off” duration (in milliseconds).

unsigned int numOfCycles

Detect at the end of this cycle number (1 – 5).


Return Values

Data Type

Description

M1X22_RET

M1X22_SUCCESS – Successful.
M1X22_FAILED – Failure.



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