The ZPL looks fine. Make sure the media installed on the GX430t printer is thermal direct. If the media installed on the GX430t is thermal transfer, the ribbon must be installed. Otherwise you may get a blank label on the thermal transfer media if the ribbon is not installed. 

thank you Steven, for ansfer.

There were some improvements yesterday but as a result still no text on the label.

This device (GX430t) is working in a factory in China. It works with custom-developed Zebra apps made by others. Other apps have text over labels. But not in my app. Label data appears when the printer is dry. The printer is printing, but the label is blank.

I tried some things. Maybe there is an error in my ZPL codes or because the GX series device does not detect it. I tried removing the printer setting code in each line at the top of my ZPL codes one by one. I removed the Image part and tried it. I removed the special characters and tried it. Finally, I wanted to print a single line of simple text. None of them yielded results.

I then encapsulated my ZPL code with square brackets. ${ }$.
This too failed. Last time I wanted to print with printDocument like a regular A4, office printer. In that method, the label was blank. I can't print anything on the label. But other applications can print successfully.

Where am I doing wrong?

Steven, thank you so much for your reply. Because there is no one to support me. And the software I developed for my client does not work in the factory in china.

I asked the people at the factory about the thermal transfer mode. I am waiting for a reply.

- I tried on the printer by deleting the ^MTT code, but the result was still unsuccessful.
- I just tried a label ZPL data with the following code on the printer, but the result was still unsuccessful.

private void simpleButton2_Click(object sender, EventArgs e)
        {
            string filename = Functions.RAWLabelTestDocName;

            String text = "^XA" + Environment.NewLine;
            text += "^FO20,210" + Environment.NewLine;
            text += "^A0N50,50" + Environment.NewLine;
            text += "^FDModel: [TEST LABEL]^FS" + Environment.NewLine;
            text += "^XZ" + Environment.NewLine;

            RawPrinterHelper.SendStringToPrinter(lblPrinterName.Text, text);
        }

Is this printer using EPL instead of ZPL?
The Setting Export .drs file I got in the printer's Properties window is the GoogleDrive link. Also, GoogleDrive link are screenshots of all Properties windows of the printer. https://drive.google.com/drive/folders/1M8JnhUqrPdqj5J7-R5Ki3Qfp4AA0IUK1?usp=sharing

How can I try to send the file.zpl file directly to the printer outside of ZPL or EPL? Is there a C# resource on this?

I can't think of anything new to solve this problem right now.

If the printer is set for EPL, then the ZPL will be ignored and the printer will not even advance a label. Since you mentioned that the printer printed a blank label, it means that the printer processed ZPL accordingly and printed a label. However, if there is no ribbon, there will be nothing on the label if the label is the thermal-transfer paper, which requires the ribbon to have the text/barcode/graphics printed on. Check if the printer has run out of the ribbon. If there is no ribbon, then the label media has to be the thermal-direct.

Hello Steven, I have forwarded your questions to the factory. I am sharing the answers and screenshots.

I also share a screenshot of another barcode software and a photo of the label printed with that program. Barcode software of 5 different customers is used in this factory. Each customer has developed special software for the label designs of their products. I am one of those customers.

Hi Steven, I wish you a good week.

They sent me the allcv information file from the device in the factory. Since I could not attach a file to this reply message, I uploaded the file to the link below. I would be very happy if you review and give feedback.

Thanks,

https://drive.google.com/drive/folders/1UwElBxFYwxhdABWeHN18JqvYLzzfoODR?usp=sharing

Hello Steven, Narrow down the issue thank you for your effort.

Yes, I am using the reference of Link-OS SDK in my source code. I am using USB protocol for connection. The screenshot of my source code is as follows. I ran code very similar to the basic ZPL thread you posted and outputs blank tags. I am using UsbDiscovery to connect to the device. I have an interface design that helps me make sure the connection. It is as in the screenshot below.

private void simpleButton2_Click(object sender, EventArgs e)
        {
            String text = "^XA" + Environment.NewLine;
            text += "^FO20,210" + Environment.NewLine;
            text += "^A0N50,50" + Environment.NewLine;
            text += "^FDModel: [TEST LABEL]^FS" + Environment.NewLine;
            text += "^XZ" + Environment.NewLine;

            RawPrinterHelper.SendStringToPrinter(lblPrinterName.Text, text);
        }

Hi Steven, I hope you had a good weekend.

Do you have any other solution for this issue?

Hi Steven, thank you.

Please refer to the below link for the document containing the screenshot of all Preferences setting windows of the device. I could not find from which setting tab to send the txt file containing the ZPL codes to the device.

https://drive.google.com/drive/folders/1M8JnhUqrPdqj5J7-R5Ki3Qfp4AA0IUK1?usp=drive_link

Hello Steven,

The factory tried the ZPL file sent directly to the printer (GX430t) and the result was unsuccessful. Tried the same ZPL file on different Zebra printer devices and it worked fine. There is a problem with the GX430t device. My client requests support directly from Zebra.

^XA
^FO20,210
^ADN,50,50
^FDModel: [TEST LABEL]^FS
^XZ

They gave me the contact information of the personnel in charge of the device. Could you please share your e-mail address with me? I will share my client's contact information with you. And I'd be very grateful if you could create a support ticket if needed.

Thanks,
Cenk