Ke yb oa rd

Sc a n

DTMF

Outp ut

(P in 17)

P ULS E

Outp ut

LED

Ke yb oa rd

Inp ut

ON

OFF

ON

Tfla s h

3

3

KEYBOARD S CAN

1

FLAS H

*

3

ENTER

ENTE R

E NTER

ENTE R

Dial S e qu e nc e

1

3 : De bounce Time

3

LND

Ke yb oa rd

Sc a n

DTMF

Outp ut

(Pin 17)

P ULS E

Outp ut

LED

Ke yb oa rd

Inp ut

ON

OFF

ON

Tfla s h

3

3

3

KEYBO ARD S CAN

1

FLAS H

*

E NTER

ENTE R

ENTER

E NTER

Dia l Se que nc e

1

3 : De bounce Time

LND

OFF

Figure 5 : Pulse Mode Timing with Tone Indicator Using ”*” or ”Tone” Key

Ke yb oa rd

Sc a n

DTMF

Outpu t

(P in 17)

P ULS E

Outpu t

LED

Ke yb oa rd

Input

ON

OFF

ON

Tflas h

3

3

3

KEYBOARD SCAN

1

FLAS H

*

3

ENTER

ENTER

ENTER

ENTER

Dial Se que nc e

1

3 : De bounce Time

Figure 3 : Tone Mode Timing with Tone Indicator (Pin 24 to any row)

ST3917A - ST3917B

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