|With one of my customers I have this really weird problem. I just describe it in a bunch of facts, to keep it short.
* It's an application that communicates with a weighbridge and visualises the current weight of the brigde (serial communication RS232) --> the scale sends over the weight continuessly
* The customer can make a ticket containing information about the transporter and the kind of product that's been transported
* When the ticket is saved, it is also printed on the connected USB HP LaserJet (P1006) printer
* pc/dev configuration: Windows XP SP3, VS2008 (C#)
The problem is that sometimes for an unknown reason, the printer does not print. The ready-LED keeps blinking but nothing happens. The application continues to work normal. When this happens, the customer opens the print cartridge cover and closes it again and then the printer starts the print job.
It's a problem that I've seen happening but I can not reproduce it.
it's not related to the data (if you print the ticket afterwards, no problem)
It's not related to hardware (did replace PC, Printer (from other brand), USB Cable without success)
I did rewrite my app so that the serial communication happens in a backgroundworker and generates an event only if the current weight is different from the previous value (this delegate for this event updates the GUI)
I did create also another backgroundworker to create and print out the document (System.Drawing is used to do this; did use Crystal Reports in the past but same problem there)
The data is stored in XML files
What I also did was unchecked the flag 'allow the computer to turn off this device to save power' for all USB Root Hubs. --> I don't have any results of that yet, since I did this just yesterday.
At this moment, I don't know where to search anymore. I can not reproduce it, I can not find any kind of pattern in the occurence of this problem, I can not tell what might cause the problem.
In summary: is there anybody with some suggestions
modified on Friday, June 26, 2009 3:56 AM