Re: [hylafax-users] Regarding USR5610 Modem

[Lee Howard <faxguy@xxxxxxxxxxxxxxxx>]

On 2005.02.22 11:54 Philip Walls wrote:

> Feb 22 14:46:10.06: [25746]: <-- [9:AT+FTH=3\r]
> Feb 22 14:46:10.22: [25746]: --> [7:CONNECT]
> Feb 22 14:46:10.22: [25746]: <-- HDLC<7:FF C8 FD F2 00 00 F0>
> Feb 22 14:46:10.22: [25746]: <-- data [7]
> Feb 22 14:46:10.22: [25746]: <-- data [2]
> Feb 22 14:46:11.50: [25746]: --> [2:OK]
> Feb 22 14:46:11.50: [25746]: SEND send PPS (partial page signal)
> Feb 22 14:46:11.50: [25746]: SEND send MPS (more pages, same document)
> Feb 22 14:46:11.50: [25746]: <-- [9:AT+FRH=3\r]
> Feb 22 14:46:11.65: [25746]: --> [10:NO CARRIER]
> Feb 22 14:46:11.65: [25746]: MODEM No carrier
> Feb 22 14:46:11.65: [25746]: <-- [9:AT+FTH=3\r]
> Feb 22 14:46:11.84: [25746]: --> [7:CONNECT]
> Feb 22 14:46:11.84: [25746]: <-- HDLC<7:FF C8 FD F2 00 00 F0>
> Feb 22 14:46:11.84: [25746]: <-- data [7]
> Feb 22 14:46:11.84: [25746]: <-- data [2]
> Feb 22 14:46:13.13: [25746]: --> [2:OK]
> Feb 22 14:46:13.13: [25746]: SEND send PPS (partial page signal)
> Feb 22 14:46:13.13: [25746]: SEND send MPS (more pages, same document)

The problem was with the sender... well, probably.  This isn't the 
"typical" USR issue that I was discussing before.  Notice that "NO 
CARRIER" (I'll explain below).

Here's the receiver's perspective:

> Feb 22 14:46:11.53: [23169]: RECV recv PPS (partial page signal)
> Feb 22 14:46:11.53: [23169]: RECV recv MPS (more pages, same document)
> Feb 22 14:46:11.53: [23169]: RECV received 16 frames of block 1 of 
> page 1
> Feb 22 14:46:11.53: [23169]: RECV/CQ: Adjusting for EOFB at row 1078
> Feb 22 14:46:11.53: [23169]: RECV: 4051 bytes of data, 1078 total 
> lines
> Feb 22 14:46:11.53: [23169]: MODEM set XON/XOFF/DRAIN: input ignored, 
> output disabled
> Feb 22 14:46:11.53: [23169]: MODEM input buffering disabled
> Feb 22 14:46:11.53: [23169]: <-- [9:AT+FRS=7\r]
> Feb 22 14:46:11.63: [23169]: --> [2:OK]
> Feb 22 14:46:11.63: [23169]: <-- [9:AT+FTH=3\r]
> Feb 22 14:46:11.82: [23169]: --> [7:CONNECT]
> Feb 22 14:46:11.82: [23169]: RECV send MCF (message confirmation)
> Feb 22 14:46:11.82: [23169]: RECV FAX (000000236): from FaxModem1, 
> page 1 in 0:06, INF, 3.85 line/mm, 2-D MMR, 12000 bit/s
> Feb 22 14:46:11.82: [23169]: <-- HDLC<3:FF C8 31>
> Feb 22 14:46:11.82: [23169]: <-- data [3]
> Feb 22 14:46:11.82: [23169]: <-- data [2]
> Feb 22 14:46:13.00: [23169]: --> [2:OK]

Basically you have the sender transmitting the PPS-MPS signal, and the 
receiver listening.  The sender finishes, and then begins to listen for 
the receiver's response.  The receiver, meanwhile waits for 70 ms of 
silence (AT+FRS=7) before transmitting the response, but it doesn't 
detect the full 70 ms of silence until 14:46:11.63, which is 
essentially the same moment that the sender detects a carrier loss (NO 
CARRIER at 14:46:11.65).  What does this mean?  It means that the 
sender reported the carrier drop for its own carrier signal.  Sigh.

If I send you a patch can you make use of it?  I'm thinking of doing 
either this:

<-- AT+FRH=3
--> NO CARRIER
<-- AT+FRH=3

(retrying the reception on a carrier loss without a CONNECT first)

or...

<-- AT+FTS=1
<-- AT+FRH=3

(specifically waiting 10 ms after our carrier drops before looking for 
the response)

instead of...

<-- AT+FRH=3
--> NO CARRIER
<-- AT+FTH=3

Lee.

____________________ HylaFAX(tm) Users Mailing List _______________________
 To subscribe/unsubscribe, click http://lists.hylafax.org/cgi-bin/lsg2.cgi
On UNIX: mail -s unsubscribe hylafax-users-request@xxxxxxxxxxx < /dev/null
 *To learn about commercial HylaFAX(tm) support, mail sales@xxxxxxxxx*