Kodak DryView 8300 Service Manual page 178

SERVICE MANUAL
The number following the "err" (1,2,3,4,5, etc.) is an incrementing count of the number of readings that
have been filtered out. When a reading is filtered out, the last valid reading is reused instead. Once the
value has again stabilized for 5 consecutive readings, the new stable value is used and the HEATER has
"recovered".
In the case below, the software was expecting a value of 2813 but measured a change from 2777 to
2813, which is too large to be valid.
The software marks this reading as an error and reuses the previous good value of 2813. The software
now watches for 5 consecutive stable readings and when it gets them, then declares recovery. The new
stable value is considered the new OK value with which to compare other readings.
PRHTCTRZ: RTD= 2777 err
PRHTCTRZ: RTD= 2813 err
PRHTCTRZ: RTD= 2814 err
PRHTCTRZ: RTD= 2814 err
PRHTCTRZ: RTD= 2815 err
The following RTD reading at 08:32:50 is the 5th consecutive stable value. The word "Stable" does not
mean identical; some small (like a degree) change in temperature is allowed, which would be the case if
the DRUM continues to heat up. This new reading of 2816 is now used to control the HEATER.
PRHTCTRZ: Recovered after
PRHTCTRZ: RTD= 2816 OK
PRHTCTRZ: RTD= 2816 OK
PRHTCTRZ: RTD= 2816 OK
PRHTCTRZ: RTD= 2816 OK
PRHTCTRZ: RTD= 2816 OK
PRHTCTRZ: RTD= 2816 OK
If there are some random RTD glitches that appear like they reoccur 26 seconds apart, this almost
invariably points to a SLIP RING problem. The DRUM rotation time is 26 seconds per revolution.
The whole point of filtering out drastically changing RTD values is to recover from problems such as the
minor SLIP RING problem with the DRUM. The software filters out the glitches and still controls the heater
successfully.
The following is a display that indicates a problem with temperature measurement that was not recovered.
Static electricity being generated in an improperly grounded PROCESSOR ASSEMBLY can scramble the
RTD data. This causes unrecoverable errors and ultimately generates temperature related error codes
such as EC 88, EC 19.
PRHTCTRZ: RTD= 2477 OK
PRHTCTRZ: RTD= 2481 OK
PRHTCTRZ: RTD= 648 err
PRHTCTRZ: RTD= 648 err
PRHTCTRZ: RTD= 648 err
PRHTCTRZ: RTD= 648 err
The sudden drop from 2481 to 648 is detected as an error by the software. Ignoring it filters out the value
of 648 and 2481 is reused.
A sudden drop like this that stays pegged at the same value usually indicates that static zapped the A/D
DEVICE. Cycling IMAGER power would be the only way to get out of this condition.
In this scenario, the RTD reading stabilized again and is considered OK. The consistent readings satisfy
the software's filtering algorithm. However, filtering is just the first line of defense. Other software error
checking is going to detect a problem with the pegged value and then turn off the HEATER.
7-10
1= 2813 PW= 94 Ave_F= 251.6
2= 2813 PW= 94 Ave_F= 251.7
3= 2813 PW= 94 Ave_F= 251.7
4= 2813 PW= 94 Ave_F= 251.7
5= 2813 PW= 94 Ave_F= 251.8
5 RTD values were filtered out
= 2816 PW= 91 Ave_F= 251.8
= 2816 PW= 91 Ave_F= 251.8
= 2816 PW= 90 Ave_F= 251.8
= 2816 PW= 90 Ave_F= 251.9
= 2816 PW= 90 Ave_F= 251.9
= 2816 PW= 90 Ave_F= 251.9
= 2477 PW= 162 Ave_F= 223.5
= 2481 PW= 162 Ave_F= 223.7
1= 2481 PW= 162 Ave_F= 224.0
2= 2481 PW= 162 Ave_F= 224.3
3= 2481 PW= 162 Ave_F= 224.5
4= 2481 PW= 162 Ave_F= 224.8
16 JUL 02 08:32:45
16 JUL 02 08:32:46
16 JUL 02 08:32:47
16 JUL 02 08:32:48
16 JUL 02 08:32:49
16 JUL 02 08:32:50
16 JUL 02 08:32:50
16 JUL 02 08:32:51
16 JUL 02 08:32:52
16 JUL 02 08:32:53
16 JUL 02 08:32:54
16 JUL 02 08:32:55
16 JUL 02 12:05:32
16 JUL 02 12:05:34
16 JUL 02 12:05:35
16 JUL 02 12:05:36
16 JUL 02 12:05:37
16 JUL 02 12:05:38
1908110 2004 December Rev. S