Data Sheet

AS2574B

Rev. 1

5

Jan. 1995

RecallFunction

A recall activation will invoke a flash (timed loop break)

or an earth recall (ER) depending on the ER pin. When

the ER pin is forced to V

ER is open (> 50 k

Ω}, an earth recall is executed.

If R is the first entry in a digit string, it will be stored in LNR

RAM.

If the R key is depressed after a digit string has been

dialled out, the recall will not be stored, and subsequently

entered digits will be buffered in the FIFO.

A recall will automatically generate a pause when a recall

is read from a memory and therecall has been stored as

an access code.

A manual invoked earth recall will pull ER high for

minimum 500 ms, but the ER pin is maintained high as

long as the key is depressed.

During auto dial an earth recall is executed with a

duration of 500 ms.

Pause Generation

Pause introduces a delay in signalling digits strings to

accommodate second and subsequent dial tones.

Automatic pauses are generated:

- during dialling out from memories when the first digit(s)

in the digit string equal the stored access code(s)

(pause depends on DT input).

- when going Off-hook by pressing LNR, MEM, or M1 -

9 (ACP).

Any pause can be terminated (shortened) prior to time

out by pressing the LNR key or a high level on the DT

input.

During ACP a pause time out, i.e. DT kept low for > 8

sec., will return the device to idle state.

Pauses are storable as digits within a string of any of the

memories by pressing 2nd # during programming.

Multiple pause entries can be stored up to the maximum

length of the digit string (18 digits/data). A pause is not

accepted in location 1 of a digit string.

If more pauses have been stored in succession, they can

all be terminated by one depression of the LNR key or a

high level on the DT pin for

≥ 1.15 sec.

SlidingCursorProcedure

To accommodate redialling (LNR) behind a PABX wi-

thout using automatic pause generation (storing access

codes), a sliding cursor protocol is implemented. If new

entries match the previous LNR 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 LNR RAM will contain the

new number.

AccessCodes

Different access codes (totally up to 18 digit/data inclu-

ding spaces) can be stored in one string. Spaces bet-

ween the different access codes are entered by pressing

the 2nd # during programming. Each access code can

contain up to 4 digits.

If one or more access codes are stored, the first entered

digit(s) in a digit string read from the RAM will be

compared with the access code(s) and if equal, a pause

is generated.

Example on programming access codes:

ENTER, 9 , 2nd #, 50

0

Release both

The first access code in this example is 9 and the second

50.