I need to print an image that is being returned to me through a web service (the data is returned as RAW) and I cannot for the life of me figure out how to print a graphic to a label with EPL.
The EPL manual defines the Graphic Write instruction as:
GWp1, p2, p3, p4, DATA
All of the parameters are returned to me, so I don't have to worry about calculating the height, width, etc., but my problem is that I don't know how to format the DATA.
The manual says DATA should be
Raw binary data without graphic file formatting. Data must be in bytes.
I've tried passing a binary string and a hex string, but nothing seems to work. There is no example on how to use this command in the EPL manual and after hours of searching online I have not been able to find a single example of how to use the command (i.e. example EPL commands that I can copy & paste to send to the printer).
Does anyone have an idea of how to use this command? Could you provide me with an example? (by example I don't mean a framework, code, etc., what I mean is just the plain EPL commands).
I can confirm that the data is in raw, uncompressed binary. It is also inverted-- that is, the 0 bits print as black, at least on my UPS-firmware LP-2844. I have no idea why all the examples from Zebra show the data as encoded into a hex representation.
It's worth noting that most print servers (HP Jetdirect, Lantronix LPS1-T, and almost certainly the Zebra built-in and external print servers) will form a binary connection to the printer if you spit data at them on port 9100 (using netcat for example):
nc printer_hostname_or_ip_address 9100 < test_file.txt
You get no feedback from the printer, except for the label having printed or not.
It takes my LP-2844 (UPS Firmware) printer about 5-6 seconds to print a label containing a 816 wide x 1218 tall downloaded bitmap onto a 4" wide x 6" tall label. It seems to be all imaging time: sending three labels at once is not any faster, and the network connection (through a Lantronix LPS1-T) is held open until the final label prints. That image is at the native resolution of the printer (203 dots/inch), and there is no dithering or resizing going on (I don't think EPL2 even knows how to dither or resize).
It might be possible to speed up the imaging time by optimizing the label into many smaller bitmaps (and horizontal and vertical line segments, and perhaps filled-in rectangular blocks). This wouldn't be a very hard optimization because the image is a single-bit black and white bitmap, and the code would be fairly simple. I don't know if it would really speed it up, though.
A more modern Zebra GX420 running ZPL with a built-in ethernet port ($500 online) can print the same label (with essentially the same graphic download encoding) in 1-2 seconds.
By the way, since I haven't yet actually answered the question, the raw EPL code for this is:
(a blank line)
N
q816
Q1218,20
GW10,10,102,1218,(124236 bytes of inverted bitmap data)
P
all the newlines are 0x0a (unix-style).
Maybe this will help, it has examples (and corrects an error in the manual). Also, it may be easier to use the GM command instead and just delete the image each time (see here for a stackexhange related question).
That being said, I've never gotten my Eltrons to successfully print an image (but my jobs don't require it).
Good luck!!
EDIT: Here's another link with example Perl code. They're aiming for Chinese characters but show how to print the Great Wave image (which oddly is Japanese).
I found that it is not possible to send a graphic to a Zebra printer with EPL using ASCII characters. The data must actually be sent as RAW data. So, for example, you can't send a graphic to the printer using Zebra Setup Utilities, or through any other means that cannot write RAW data from a file directly through the printer.
The only way around this I've found is to create the label as an image and send that image to the printer via a print command within your application.
Related
I have a PostScript file with image and text. I want to print it to a laser printer so that the images print in a halftone round pattern.
I am trying to print it from the command line. I would prefer a PDF output first and then I'll print to the laser printer.
I have an HP Laserjet P2015 printer installed in Windows 10.
gswin64c.exe -dQUIET -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=output.pdf test.ps -c "<< /HalftoneType 1 /Frequency 37 /Angle 45 /SpotFunction {180 mul cos exch 180 mul cos add 2 div} >> sethalftone"
The PDF file is generated. However, the images does not appear to be in Round Halftone format. I see no change in the image.
This is the original Image
I want the printout to look like this: Required output
For some reason the output is the same as the original.
pdfwrite doesn't create monochrome output, so no, the output won't be halftoned. The whole point of the pdfwrite device is to maintain the output as close in quality as possible to the input.
There is no way to get monochrome output from pdfwrite unless the monochrome is in the input.
If you instead use a monochrome output device (e.g., tiffg3 or tiffg4) you should see a difference, unless the input file (which you haven't supplied) also sets a screen, in which case the last one encountered will take effect. That is, if the PostScript input file specifies a halftone screen, that's the one that will get used.
What you are asking for is what I might generally describe as a hard problem, probably much harder than you expect.
Your best bet is to send the PostScript directly to the printer, since it supports PostScript.
Problem 1; your PostScript file may already contain a halftone in it which overrides the one you want to use. You can usually prevent that by redefining the sethalftone and setscreen operators:
/sethalftone {pop} bind def
/setscreen {pop pop pop} bind def
You do that after you'[ve defined your own halftone, obviously. Or you can just edit the PostScript file and remove the halftone definition, its usually not that hard to find.
Problem 2 is that printer manufacturers sometimes 'tweak' the interpreter to always use their preferred halftone and prevent you overriding it in PostScript. The only way to find out if that's happening is to try a quick test; print a simple image with the default screen, then set a really coarse screen, say 10 lpi and print the same image. If there's no difference then you know that's not a viable option. If there is, then you can just set the screen you want.
Now, if the printer won't let you change the halftone then the only solution is to render the PostScript to an image using Ghostscript (which will let you change the halftone) and then send the resulting image to the printer. You will need to use a 1 bpp device, something like tiffg3 or tiffg4 should work fine.
The problem here is that you need to ensure that the image fits on the media of the printer, because if it doesn't then the likelihood is that the printer will slightly scale down the image so that it does fit, thereby squashing the halftone cells.
Even more subtly, the printable area of the media in the printer may not be the same as the size of the media. Paper handling can mean that there are some areas of the paper that can't be printed on, and the variability in the feeding of the paper can mean that the printer will refuse to print right to the edges anyway. Because if it did, and there was, say, a 1 mm deviation in the paper handling, then 1 mm of the edge would 'fall off' and there would be a 1 mm white gap at the other edge...
I use simple GDI DrawText to output blocks of text to a printer.
The font used in the sample is Segoe UI. But you can use Arial or others too. It doesn't matter.
The algorithm for large text blocks is simple. DrawText is called with DT_CALCRECT with a kind of binary search for the length to get the largest possible text to print. Than DrawText is called without DT_CALCRECT to print the block.
Simple one line text column text is written with one call to DrawText with the given coordinates of the rectangle.
The result is real strange and can be seen in this sample PDF.
Just look on the first line after the header. You can see the text "Test, Test" and you can see the strange kerning here perfectly. The kerning os sometimes so bad, that you can't even read the words.
How to get around this? Is it a problem with the used printer? Is it a problem with DrawText?
The distance between some chars in a word seem to be random in some case. Some spacing are wide other to narrow. The letter combination looks strange unreadable and ugly.
I tried different fonts and printers but the problem just varies but it is always present.
I know about ExTextOut and the capabilities to define the distance/kerning between all chars, but frankly I don't want to care about this. I just want that DrawText behaves on the printer like on the screen. The stuff works on the screen perfectly.
Added 2018-08-23 08:49 GMT+2*
To the code (it is a complex printing engine).
1.Fonts to print are created simply with CFont::CreatePointFont, so the LOGFONT structure is cleared to zero and no additional flags are used except point and face.
2.The mapping mode is MM_ANISOTROPIC. To scale what is seen on the screen and what is to be printed I just use the size of a komparable object (textblock) on the printer and the same size on the screen. The real values for the sample printout to the Microsoft PDF Printer are as follows, the real way I calculate them is not of interest:
m_pDC->SetMapMode(MM_ANISOTROPIC);
m_pDC->SetViewportExt(2363,100);
m_pDC->SetWindowExt(355,13);
This has the effect that the height of a line in LPs is 13, the average character width in LPs is 6...
I have acquired an Epson thermal printer (TM-T82II) with a control utility (APD5) that allows me to configure and test the printer. I use the utility to (try to) print barcodes, but cannot find any documentation on how to make use of the Code128 support I need.
I want to print out a Code 128 barcode for "PQR123X1122331807110011223344". I seem to be able to do this by specifying a test string of "{APQR123X1122331807110011223344" to encode the string in Font A, and likewise use "{BPQR123X1122331807110011223344" to encode it entirely in Font B. Both generate barcodes too wide for the paper I have. However, there is a large run of digits after the "X" which is more efficiently encoded in Font C and that I know will fit (I have an example from another printer). The obvious thing of using "{APQR123X{C1122331807110011223344" produces garbage.
Can anyone point to documentation that unravels how Epson do font-switching in Code 128?
#Omatai,
Epson's ESC/POS printer language does not use fonts for rendering barcodes. If you are directly sending escape codes to the Epson printer, GS w is the command to set the barcode width in ESC/POS, where w is a number between from 2 (thinnest) to 6 (thickest) which specifies the width of the barcode's minimum element. The actual measurement is dependent on the model of the Epson printer.
Epson ESC/POS Documentation: https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=2
To help you further, this group would need to know more about the programming model that you are using and the associated code that you are attempting to use.
Terry Warwick, Microsoft
I am working on a set of ZPL validation routines which parse arbitrary ZPL files, sanitize them, edit certain key commands (label length, print speeds, etc), and extract some useful information.
Since this printer is generating labels for a free-running shipping line I really need to know how long it's going to take from the moment I send the ZPL file to the printer until I'll be ready to apply the label. It is clear that the print time is directly linked to the label length and print speeds, but the label render time (conversion of ZPL into ready to print image in printer memory) is less obvious.
Since I'm printing label contents provided by numerous third parties, I can't simply measure the time for the labels. I've asked Zebra and gotten no guidance, so I'm wondering if anyone has an idea of how to estimate the render time? Am I stuck trying to estimate the processing time of every individual ZPL command?
My experience over the last couple of years working with differnt zebra printers (Z4M, ZM400, GK420t) is, that the label that is send to the printer is printed almost instantaneously.
I am developing a Windows Mobile App that requires printing into a Zebra printer. Problem is, I do not have the printer with me here in my country since the client did not provide any.
My approach was to design a label first in ZebraDesigner2, then print out the label into a text file. Printing the label to a text file instead of a printer sends out the ZPL Code to produce the label I was trying to print. Hence, I can generate ZPL codes faster by designing a label first then seeing the ZPL code. Kinda like having a drag and drop GUI with a background XML.
Say that I have this simple label that contains this text:
Hello World!
If I print this in ZebraDesigner2 it would be written to my text file as:
CT~~CD,~CC^~CT~
^XA~TA000~JSN^LT0^MNW^MTT^PON^PMN^LH0,0^JMA^PR5,5~SD15^JUS^LRN^CI0^XZ
^XA
^MMT
^PW609
^LL0406
^LS0
^FT1,29^A0N,28,28^FH\^FDHello World!^FS
^PQ1,0,1,Y^XZ
My main question is, which one do I include in my C# Code if im going to send this code to the printer via my Windows Mobile C# app? Do I include the part with ^XA until ^XZ? I believe that CT~~CD,~CC^~CT~ should not be included in my code If im not mistaken.
Late answer, but since this is getting viewed...
The CT line and first set of XA..XZ sequence sets up the modes, label length, printable area, etc.
If you remove those, it will take those settings from the label/printer settings, which is usually what you want. The printers can sense the length and width of the label.
Leaving them in can cause big problems, because if you define the printable area in your label, and then the next label type submitted does not, it will use the settings you have defined -- which can cause blank areas in the label, eg. cutoff USPS Label barcodes that are printed after your Zebra Designer custom labels.
Found this out the hard way - leave those out, and you should leave out of the remaining XA..XZ sequence the MMT, PW609, LL0406, and LS0 as well - your Hello World will not be affected.
If you really want to limit the area printed to, set up margins inside the printable area, etc, refer to the manual.
you have to look at the programmers guide before you remove anything of the code. The CT~ command for example changes the control prefix.
Search the internet or zebra.com site for "ZPL Programming guide".
So, leave the text file as is and then include that into your windows mobile application.
PS: zebra offers SDKs for label/receipt printers: http://www.zebra.com/gb/en/products-services/software/adapt-software.html
PS2: without a test printer you may get bad final results.