SA589 Sames, SA589 Datasheet - Page 7

• Manufacturer Part Number: SA589
• Description: LD/DTMF SWITCHABLE DIALLERS WITH DEDICATED KEYS FOR 20 MEMORIES
• Manufacturer: Sames

Timed Break & Earth Loop Recall
The SA589 supports both TBR and ELR and offers a common operating protocol in both
cases.
After a recall (Flash) operation, the dialling mode selected via the SELECT pin will be restored.
Also, only the digits dialled after the ELR/TBR operation will be retained in the LNR store
A TBR (Flash) of 100ms or 270ms
output goes low in order to produce the line break. When in DTMF mode, the MF OUT output
also goes low for the duration of the break.
ELR is supported via the column 3 pin. If this pin is connected to ground for a minimum of 20ms
during an ELR operation, the chip will offer the same operating protocol as for TBR.
This may be achieved by use of the circuit shown below in Fig. 3, or by use of a double contact
switch.
(1)
(2)
Dialling from memories
The SA589 must be 'off-hook' and idle:
1.
2.
All keypad positions are disabled whilst memory dialling is in progress.
Press the appropriate memory key (S00 - S19). Dialling will now start.
If dialling halts due to a Pause or an LD to DTMF changeover in the memory, the PAUSE
OUT pin will go high (logic '1'). Further dialling can be resumed by pressing the PAUSE/
CONT key or alternatively, by pulling the Column 4 pin low (for a minimum of 14 ms)
to achieve the same result thus allowing an external timer circuit to be used. The
PAUSE OUT output is reset when dialling resumes.
Other options are available.
Other TBR (Flash) periods are available as mask options
C O L 3
DR-00685
2 1
SA589
2 2
Fig. 3 Earth loop recall
(2)
is generated when the TBR key is pressed. The MASK
SA589 FAMILY
7/14
(1)
.