Re: flexfax: Strange problem : modem capabilities not reported to fax machines

[Dmitry Bely <dbely@mail.ru>]

Andrea Albarelli <andrea@side7.it> writes:

> I tried to set :
> 
> Class2CQCmd:            "AT+FCQ=2,2+FRY=10"

Enables receive copy quality *correction* by DCE. +FRY it *useless* (ECM is 
not supported).

> But all i got are a few retrain negative :
> 
> Apr 04 16:02:29.47: [13592]: --> [7:CONNECT]
> Apr 04 16:02:29.47: [13592]: RECV: begin page
> Apr 04 16:02:29.47: [13592]: RECV: send trigger 022
> Apr 04 16:02:29.47: [13592]: <-- data [1]
> Apr 04 16:02:33.11: [13592]: RECV/CQ: Bad 2D pixel count, row 73, got 2117, expected 1728

... and DCE had corrected 13 of 14 bad lines.

> Apr 04 16:02:52.57: [13592]: RECV: 32645 bytes of data, 326 total lines
> Apr 04 16:03:14.57: [13592]: RECV: 32615 bytes of data, 510 total lines
> Apr 04 16:03:36.64: [13592]: RECV: 32658 bytes of data, 731 total lines
> Apr 04 16:03:59.03: [13592]: RECV: 32611 bytes of data, 895 total lines
> Apr 04 16:04:21.09: [13592]: RECV: 32625 bytes of data, 1049 total lines
> Apr 04 16:04:21.76: [13592]: RECV/CQ: Bad 1D pixel count, row 1108, got 0, expected 1728
> Apr 04 16:04:21.76: [13592]: RECV/CQ: Bad 1D pixel count, row 1109, got 0, expected 1728
> Apr 04 16:04:21.76: [13592]: RECV/CQ: Bad 1D pixel count, row 1110, got 0, expected 1728
> Apr 04 16:04:21.76: [13592]: RECV/CQ: Bad 1D pixel count, row 1111, got 0, expected 1728
> Apr 04 16:04:21.76: [13592]: RECV/CQ: Bad 1D pixel count, row 1112, got 0, expected 1728
> Apr 04 16:04:21.76: [13592]: RECV: 1230 bytes of data, 1113 total lines
> Apr 04 16:04:21.76: [13592]: --> [16:+FPS:2,462,E,4,0]

found 14 bad lines and 4 consecutive bad lines of total 1122. What was +FRQ 
values?

> Apr 04 16:04:23.07: [13592]: --> [6:+FET:0]
> Apr 04 16:04:23.07: [13592]: RECV recv MPS (more pages, same document)
> Apr 04 16:04:23.07: [13592]: --> [5:ERROR]
> Apr 04 16:04:23.07: [13592]: MODEM Command error
> Apr 04 16:04:23.07: [13592]: RECV send RTN (retrain negative)  
> 
> By the way, note the constant 1D errors ath the end of the page ( the last
> lines of the page ). I always get them, also with good line and good fax file
> as result ...

It was RTC -- six consecutive EOLs, indicating the end of page. Always
present, not an error.

>  they prevents me to enable +FRQ, as they raise the % of bad lines
> ( without reason ).

I doubt that the modem count them as errors ( RECV/CQ messages above was
printed by the Hylafax G3 decoder and have nothing to with the modem's
quality checking routines). Anyway they cannot significantly change percent 
of bad lines: having a page about 1000 scan lines, 5 bad lines will
decrease PGL only by 0.5%. Note that +FRQ do not enable quality control --
it just sets necessary thresholds. If you does not explicitly specify it
(and turn on CQ by +FCQ), default thresholds will be used.

> Please help me, you are my last hope ;-)

Read carefully Class 2.0 standard/modem manual and you will succeed :-)

Hope to hear from you soon,
Dmitry