Fax Protocols; G3 Ecm (G3 Error Correction Mode) - Konica Minolta magicolor 4690MF Service Manual

15. Fax Protocols

15. Fax Protocols

15.1 G3 ECM (G3 Error Correction Mode)

• G3 ECM is the error correction system newly recommended by consultative committee
of International telephone & telegraph of 1988.
• By G3 ECM, documents are divided into blocks (called partial page) for transmission. If
any error takes place in any frame (one partial page consists of 256 frames) on a partial
page, the receiving party generates the retransmit request with erroneous frame num-
bers.
Here is an example where frame 1 and frame 3 are subjected to error:
Partial page
(High-speed Modem Sig-
nal)
300 dps Modem Signal
Re-transmission for error
(High-speed modem Sig-
nal)
300 dps Modem Signal
260
Transmission
Field Service Ver. 1.0 May 2008
Receiving
Error
Note:If one page end and
consists of plural num-
ber of partial pages,
PPS.
NULL signal is trans-
mitted from the trans-
mission side.
Partial page end and End
procedure
Re-transmit request (MCF
is repeated if there is no
error)
Re-transmission
Partial page end
Message check (Received
without error)
4139F3C555DA