The telephone features (di-
alling, voice communica-
tion) can also be used
when the machine is
switched off.
When the handset goes
off-hook or the On Hook
Dial key is pressed, the di-
aller is powered by the DC
voltage from the line.
Then the dialled digits are
directly informed to the di-
aller.
2-3. Automatic Dialling
When the machine starts to dial, the TF relay switches up to close the DC loop. After the HOOK signal goes low to
indicate that line current is detected, and the modem detects dial tone at TONE (see the diagram on page A-1), the
dialler starts dialling. Then the machine waits for the line connection and CED before it starts sending the fax mes-
sage. If busy tone is detected before line connection, the machine will disconnect the line.
2-4. Dialling Method (Pulse/Tone)
The LIU has a mechanical switch beside the modular jack to select either pulse dial or DTMF dial. This switch can
be accessed by the user (in most countries). The dialler checks the setting of this switch every time the FCE de-
tects off-hook, then dials the number using the indicated method.
2-5. PSTN Access from behind the PABX
When the machine is behind a PABX, the user can program which type of access method is required.
Loop Start:
The user has to program an access code with Function 15.
Ground/Flash Start:
The user has to select GS/Flash with Function 15, and select the function of the R (Recall)
key either for Ground Start or Flash Start with the slide switch at the rear of the machine.
After the DC loop is closed, the machine detects the line current, detects PABX dial tone, accesses the PSTN using
the correct method, detects PSTN dial tone, then dials the number.
2-6. Country Settings
Each country setting is programmed in the ROM on the FCE. The FCE passes the dialling parameters to the dialler
on the LIU through the photocouplers, depending on the country code setting on the LIU.
LIU
OPU
FDU/FCE
LCD
LEDs
Other Keys
IC601
T7931
Dialler
PCD3344
Pulse/Tone
GS/Flash
Photocoupler
Country
Code
Speech
Circuit
GND Start
Off-hook/
Fax-Tel
Relays
To/From
the Line
Handset
12 Keys
Dialpad
DC Power supplied from LINE
No power
supplied
PHONE-A/B
VCC-1
LINE-A/B
LIU/OPU Block Diagram - Power OFF
PulseTone GS FS
LINE
Ground Start
Pulse Tone GS FS
LINE
Flash Start
A-3