6/22

SA2532

sames

Sliding Cursor Procedure

To accommodate easy and uncomplicated redialling (LNR) behind a PABX, a sliding

cursor protocol is implemented.

If new entries match the previous RAM contents,

pressing the LNR key will dial out the remaining digits.

If there is an error in matching, the LNR will be inhibited until next on-hook, and the RAM

will contain the new number.

Tone Generator

The tone generator incorporates the DTMF tones and 3 basic frequencies for the tone

ringer.

DTMF Tones

The DTMF Tone Generator creates 12 Tones in compliance with CCITT Recommenda-

tion Q23. Signal levels are altered by Mask Option. High group frequencies have a level

2.6dB higher than those of the Low Group.

Details of the DTMF Tones are:

Low group

Digit 1-2-3

697Hz

(Error = -.074%)

Digit 4-5-6

770Hz

(Error = -.679%

Digit 7-8-9

852Hz

(Error = -.621%)

Digit *-0-#

941Hz

(Error = +.139%)

High group

Digit 1-4-7-*

1209Hz

(Error = +.533%)

Digit 2-5-8-0

1336 Hz

(Error = +.176%)

Digit 3-6-9-#

1477Hz

(Error = -.141%)

Errors are calculated with reference to a base clock of 3.58MHz and at ambient

temperature of 24°C. They exclude tolerance errors in the base frequency.

KEYBOARD ARRANGEMENT

Figure 2

DR-00709

R3

R4

LNR/CONT.

#

8

9

PAUSE

R2

R1

C1

4

MUTE

C2

5

1

R

0

R2

*

C3

6

2

C4

7

3