Zebra RW420 is printing the ZPL commands to get TID

Question

I am trying to printing TID FROM ZPL COMMANDS

getting JJL179464

can anyone please tell me what is this character

Answer 1

To partially answer your question:

Are you reading an ASCII encoded data? Because your result: "JJL179464" does not look like a valid RFID tag data, unless it is in ASCII. Data encoded in RFID tags are encoded in binary. Depending on reader settings, the data can be outputed in binary, hexadecimal or ASCII format. Judging by the first three symbols "JJL", your reader is set to output ASCII data, or there is an error in your code.

Try to answer us the following questions:

• What are you trying to achieve?
• Provide us your code. (whole, structured)
• What device are you using to read the RFID tag?
• Provide us the settings of your reading device. (unless they are a part of the code)
• Do you know the data content of the RFID tag you are trying to read? That means, can you validate that the reading was successful?

Edit:

Thank you for your code:

^XA

^FN1^RFR,H,0,12,2^FS^FH_^HV1,256^FS

^XZ

It seems that there could be several issues in your code.

Firstly, your ^HV command is incomplete. It is missing 3 parameters. The first one (third parameter) sets the data prefix. Next one data termination. And the last one specifies when to return data. You should include all of them in the ^HV command.

There is already a good example how the ^HV command needs to be set: ^RFR,^FN1,^HV1 not sending output to computer

The second issue, at least I think that it is an issue but I don't have the means to verify it, is that you are using ^FH_ command. There are no hexadecimal values for encoding special characters in your code, so there is no point in using it. So I would try to omit it.

Also, I am not sure about the order of commands. The ^FN1 command should be after ^RFR and before ^FS commands.

Try this code:

^XA

^RFR,H,0,12,2^FN1^FS^HV1,256,HEADER,TERMINATION,L^FS

^XZ

That should give you output in format:

HEADERhexadecimaldataTERMINATION

It is a little bit hard to read, but if it will work, then you might proceed to format it nicely. The words HEADER and TERMINATION serve as prefix and postfix of data from ^RFR command. So if this will work you can replace them with brackets or whatever suits your needs.

I am also concerned about 2 things:

• The number of bytes to read - 12. Usually it is 8, but it varies depending on the type of RFID tag and the data format. I don't say that it is a mistake, just unsual to me.
• The last parameter in ^HV1 command may be "F" instead of "L". The "F" is default value and it seems that in your case it was working with it. At least you got some output, so maybe it should be "F". But try it with "L" to get a response for each label. "F" means getting a response after the entire job is done.

I hope this will work. Currently we are in lockdown and I don't have the means to verify this on real devices. But theoreticaly it should help. Please let me know the results.