Hello all,
Scanner: hp scanjet 2400
using sane-backends-cvs20051124
Expected completion date: unknown, it is ready when it is ready
Update from previous post:
key: - previously reported; + update :
- Head moves two times the expected distance.
- Excessive time in genesys_warmup_lamp()
+ excessive time appears to be a result of an incorrect formula.
(the source was patched to force SANE_STATUS_GOOD, thereby ignoring
the frontend setup, and attempting to be sure that head movements were
OK. I am to look into the frontend setup later)
- There was no image in the STDOUT output (file size 1523712)
- Status register for lamp reports OFF, but lamp remains ON.
- Head remains where the scan stopped.
+ This is a FEATURE, not a bug. The scan process depends on every detail
being expected and correct. When a status other than SANE_STATUS_GOOD
is encountered, all processing stops whereever it was. This is good,
because it assures that there can be no damage to the scanner as a
result of an unexpected reply from the device. The cause of the
problem was a result SANE_IO_ERROR, reported at the end
of the scan (miscalculation of bytes expected/received)
- In lineart mode, depth:1 was what I expected. depth:8 was reported.
NEW:
+ The device responds inconsistently to the same scan request.
When the same request is executed sequentially many times, on the
odd-numbered attempts, the scan completes, and goes to end of task.
On even-numbered attempts, the scan head never moves off of the home
position. (reading bulk data: Error during device I/O)
The error comes from not properly setting up the frontend during
the lamp warmup.
NOTE: to duplicate this problem, install from cvs referenced above.
The source code is patched (see below) to force SANE_STATUS_GOOD
in function genesys_warmup_lamp().
Use scanimage from SOURCE_TOP_DIR/frontend/scanimage.
Execute the bash command as shown below, substituting your
{BUS}/{DEVNUM} as shown in /proc/bus/usb/devices file for your scanner.
REMEMBER to keep the image size small until the size of the image
is corrected.
#!/bin/sh
scanimage -d genesys:libusb:{BUS}:{DEVNUM} --resolution 150 --mode color -t 1 -l
80 -x100 -y 30 2>scan.log 1>image.pnm
#end
PATCH (DO NOT APPLY) This patch was how SANE_STATUS_GOOD was forced
from genesys_warmup_lamp(). The frontend is not setup right, so
the image is not correct, but it demonstrates motor handling of
the scan head and the inconsistent response from the device.
--- sane-backend-20051124/backend/genesys.c 2005-12-02 00:25:55.000000000
-0600
+++ sane-backend-hack/backend/genesys.c 2005-12-02 00:24:45.000000000 -0600
@@ -3419,6 +3419,12 @@
DBG (DBG_error,
"genesys_warmup_lamp: warmup timed out after %d seconds. Lamp
defective?\n",
seconds);
+ if (seconds > 40) { /* FIXME GPM: remove 6 lines here */
+ DBG(DBG_info,
+ "genesys_warmup_lamp: ** ENOUGH (FIXME) **\n");
+ status = SANE_STATUS_GOOD;
+ goto FIXME_hack_trick;
+ }
status = SANE_STATUS_IO_ERROR;
}
else
@@ -3427,6 +3433,7 @@
"genesys_warmup_lamp: warmup succeeded after %d seconds\n",
seconds);
}
+FIXME_hack_trick: /* FIXME remove this GPM */
free (first_line);
free (second_line);
return status;
---- end-of-patch
best regards,
Gerald
--
