4 Replies Latest reply on Nov 10, 2018 5:23 PM by Tim Smith

    Reading rfid tag from label printed from another host

    Robert Tobin

      Hello, I have an enquiry about a project from a client with the following Zebra RFID Label Printer,

       

      Zt610RFID          ZT61043-T0E01C0Z

       

      They have an existing application which is printing labels to this printer across USB      (their existing system cannot  Encode RFID Labels)

       

      They have asked us to check if we can do the following:

       

      1)     Use RFID labels with a unique identifier already encoded on the label so that we don't need to encode the labels when printed

       

      2)     As the labels are printed from Computer 1, can we connect Computer 2 at the same time to the printer using another connection (Serial?)

       

      3)     When Computer 1 sends a job to print 5 labels, Is it possible to read the RFID tags for these 5 labels as these are printed and send this to Computer 2 so that I can see the unique identifiers of the RFID Tags

       

      Would appreciate some feedback if this is possible,

       

      Thanks

       

      Rob

        • Re: Reading rfid tag from label printed from another host
          Steven Si
          1)     Use RFID labels with a unique identifier already encoded on the label so that we don't need to encode the labels when printed

           

          Sure, we can do that by treating the RFID tag enabled labels as regular labels. But what's the benefit of using an RFID enabled printer to printer labels on RFID tag enabled labels?

           

          2)     As the labels are printed from Computer 1, can we connect Computer 2 at the same time to the printer using another connection (Serial?)

           

          A serial port connection is kind of one-to-one connection. We cannot connect a printer to multiple computers over serial connection. If we want to have 1-to-many connection, we can connect a printer to the network. Then multiple computers on the network can connect to the same printer.

           

          3)     When Computer 1 sends a job to print 5 labels, Is it possible to read the RFID tags for these 5 labels as these are printed and send this to Computer 2 so that I can see the unique identifiers of the RFID Tags

           

          Yes, it's possible. The ZPL Programming Guide has documented how to read the RFID tag through the SGD commands. If the computer 1 is used to send the printer commands to enable the RFID tags, there is no need to read the tag back, because Zebra RFID printer guarantees the encoded data on the tags matches with the data to be encoded. If they don't match, a void label will be printed.

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            • Re: Reading rfid tag from label printed from another host
              Robert Tobin

              Thanks Steven,

               

              Yes I see the irony of using an RFID printer and not encoding the actual labels,

               

              Customer has these printers already and their existing system cannot encode rfid labels (they cannot make changes to this system) so we are looking at alternate solutions for them,

               

              Computer 1 will be connected to the printer over usb and will print the labels (no rfid encoding, just print labels)

               

              What I want to do then is to connect Computer 2 over Lan \ serial and read the rfid tags as they run through the printer (again no encoding, just read the tag as it runs through the printer)

               

              Rob

                • Re: Reading rfid tag from label printed from another host
                  Steven Si
                  Customer has these printers already and their existing system cannot encode rfid labels (they cannot make changes to this system) so we are looking at alternate solutions for them,

                  You may also want to check if these existing printers have the RFID encoder. The RFID encoder is a separate component and field-installable.

                   

                   

                  What I want to do then is to connect Computer 2 over Lan \ serial and read the rfid tags as they run through the printer (again no encoding, just read the tag as it runs through the printer)

                   

                  We can use Computer 1 (the same computer) to read the RFID tag and print the labels. We don't need Computer 2 to do the read. If we use one computer to print and another one to ready, we are getting into the situation where the synchronization of two computers is a challenge. With one printer, we can do a RFID read first and then a label print. This way, we know exactly which RFID tag value comes from which label.

              • Re: Reading rfid tag from label printed from another host
                Tim Smith

                Robert,

                I had made serial Y cables from monitoring communications into 2 rs232 ports on a single computer to log data going both directions. Also a Y cable for connecting both a serial printer and scanner to the same RS232 port on a computer.

                 

                What you are looking for is along the same lines. RS232 doesn't have a problem sharing an output or splitting send and receive to 2 different endpoints. RS232 ports won't break if 2 outputs are wired funny and connected together. It just won't transfer data.

                 

                I expect the printing computer(device) is a legacy device and can't be touched. You can use a custom serial Y cable on the printer.

                You need pin 2 and 5 to come from the printer to the monitoring computer.

                Then pin 3 and 5 to the legacy computer that is printing. The printing computer may also need the other control pins so the printing application knows the printer is ready.

                 

                I found this on amazon.

                SF Cable: DB9 Male to 2 Female Serial Rs232 Splitter Cable 12 Inches

                If you have a volt meter you can test the wiring.

                Otherwise I would use pliers and break all the pins except 2 and 5 on one leg and name it monitor. Then break off only pin 2 on the other leg and and name it printing computer.

                If it doesn't work and you ordered 2 cables, the substitute pin 3 in place of pin 2 in the above....

                oops version if it doesn't work.. I would use pliers and break all the pins except 3 and 5 on one leg and name it monitor. Then break off only pin 3 on the other leg and and name it printing computer.

                 

                You post was from a long time ago but thought maybe it could help.

                 

                ---

                Your other choice is to have the legacy computer connected to the monitor computer via RS232 cable. Then the monitor computer connected to the printer. Your application would pass through what it receives in port 1 out to port 2. Then log what it received back from port 2 with the RFID tag information.  In this situation it could store the label information being printed along with the RFID information.

                ---

                Another choice is to use a  $20 microcontroller connected as a usb keyboard.The RS232 would be monitored by it and it would be entered into the keyboard.  This may make it possible for the legacy program to actually store the RFID tag data.

                Tim