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We are trying to print a batch of labels onto a Zebra printer. However, there are two problems: - Sometimes some labels are missing - Sometimes some labels appear in the wrong order

The Zebra printer is setup as a Text/Generic printer in Windows. We copy temp-files with ZPL to the printer. Each label is individually copied to the printer (using .NET File.CopyTo(...). Sometimes the number of labels/files sent to the printer is > 1000.

Due to logging we are pretty sure all the labels are copied to the printer queue correctly and also that they are copied in the correct order.

Any suggestions?

Undo
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Poppert
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  • Hi Poppert, were you able to figure out the solution to this? Thanks! – blue piranha Feb 19 '16 at 17:08
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    Well, we ended up creating one large zpl file containing all labels and sending all of that in one large file to the printer. – Poppert Feb 22 '16 at 08:20
  • Thank you. I did the same and it worked. – blue piranha Feb 23 '16 at 15:40
  • I came across a similar issue, when trying to print 50 labels at a time ,as a single file, but the printer stops in the middle of printing, flashes red light and prints blank page , then prints one label and then stops, The documentation mentions that this could be a memory defragmentation . But when tried to the 50 files as separate files, it starts printing in out of order – Mittal Aug 22 '21 at 18:04

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If you are connecting to the printer on the network the printer can only allow a limited number of connections. So if you send many labels at once the printer will accept some of the connections, but refuse the others. The OS will then attempt to reconnect but that will not be in order.

You have two choices: open a connection to the printer and send all the jobs to that connection or merge the print jobs into a single file and send that.

banno
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  • Any idea what the limit is on those connections. I'm having similar issue. We have a printer group of 10 zebra printers and round robin groups of labels to them but still this is an issue. – Jason Duncan Dec 11 '17 at 19:31
  • 8 or 9 unless you are using older printers with the parallel port print server which allows 3 connections. Is your issue with refused connections or out of order labels? – banno Dec 16 '17 at 01:18
  • I am currently trying to determine if these are refused connections. We are missing labels and/or the labels are out of sequence. Both are happening and even having duplicate labels. Sequence is based on how SAP sent them to the windows print server. There is no issue here that I can see spools from SAP seem to match Windows print queue. Nothing is getting hung in the windows print queue. The zebra printers are 105SL and 105SL+ devices and we are sending 100s of labels per "batch" to each printer. Over the 10 printers it may be multiple 1000s of labels in total. – Jason Duncan Dec 17 '17 at 10:06
  • 105SLs use the older print servers which allow 3 connections. If you are attempting 100's of individual connnections to the printer you are bound to get missing and out of order labels. That would not explain duplicate labels which is more likely the windows print queue trying to account for refused connections, but I am not certain on that... It would be a good exercise to look at a network sniff of the TCP connections going to the printer. – banno Dec 20 '17 at 16:44
  • Thanks for the info. We were able to resolve this issue. Well so far there have been no more issues. The old setup was SAP --> Windows Print Server --> Zebra 105SL. We took the Windows print server out of the equation and setup the Zebra 105SL as raw TCP/IP printers directly in SAP. After almost 1 week we have had zero missed labels, no duplicate labels and order has been 100%. – Jason Duncan Dec 21 '17 at 21:08