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Flow control – ZyXEL Communications 2864 User Manual

Page 170

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15–16

This message includes the connection speed and the fax parameters.

After each fax disconnection, the following result code is sent back to the DTE:

DISCONNECTnP

This result code informs the DTE of the disconnecting status.

The basic AT commands

ATV0

and

ATQ1

do not affect the above

CONNECT and

DISCONNECT status report result codes. The modem will always return the same
status format as above.

Flow Control

In extended fax AT command mode, the modem always uses hardware (CTS/RTS)
flow control. The flow control signaling used while sending a fax is:

CTS is used by the modem to flow control the DTE. When the modem turns
CTS off, the buffer inside the modem is full and cannot accept any more data.
The computer should send data only when CTS is ON.

RTS is used by the computer to signal the modem that the fax message is fin-
ished. As soon as RTS off is detected, the modem starts the post message hand-
shaking to make sure that the remote facsimile has received the fax message
successfully. Then it hangs up the phone and sends a status report to the DTE.

If you want to send a multi-page fax, just add the

RTC signal between the fax mes-

sage of two pages. The modem detects the

RTC signal automatically, handshakes the

multi-page procedure with the remote facsimile and sends the next page message.

S

nnnn

Fax connection speed; nnnn is a 4-digit number representing
the connection speed. nnnn =1440, 1200, 9600, 7200,
etc., whereby 1440 and 1200 stand for 14400 and 12000.

V

n

Vertical resolution;

n

= 0 or 1.

T

n

Coding scheme;

n

= 0 or 1.

R

n

Recording width;

n

= 0, 1, or 2.

L

n

Recording length;

n

= 0, 1, or 2.

C

n

Scan line time;

n

= 0 to 7.

P

Remote fax number.

DISCONNECT0

Disconnects with remote confirmation.

DISCONNECT1

Disconnects without remote confirmation.

P

Remote fax number.