Solving Voids and Best Practices on an RP4T Printer

Solving Voids and Best Practices on an RP4T Printer

Article ID: 10840164




Solving VOID Issues with an RP4T Printer

Applies To

RP4T Printers


1. The first step in solving the voids with the RP4T printer is to ensure that it is calibrated to the proper label length. In order to calibrate any mobile printer you need to send the appropriate commands to do so, see below for these commands.

***Also ensure that config.sys file has proper media type specified within it (bar/gap)***

Black Mark/Bar Media:

! U1 setvar "media.sense_mode" "bar"
! U1 setvar "device.languages" "zpl"

Gap Media:

! U1 setvar "media.sense_mode" "gap"
! U1 setvar "device.languages" "zpl"


Note: Verify calibration by hitting blue feed button to ensure that the printer will feed one tag properly

2. Do your RFID Tags meet Zebra's Placement Specification?  Check the Placement Specification for the Tag Type you are using.  Read More>>  Please ensure that the tag type you are using is within the guidelines for the printer. At this point, go through the front panel of the printer and select “Menu”.  Once in the menu, select the “Radios” option.  In the radios option go under “RFID”.  Select “Settings” and then “Tag Calibration” at this point.  First you want to “Restore” within the tag calibration section.  Once the restore is complete, “Run” the tag calibration.  The printer will proceed to slowly feed out several labels to calibrate the appropriate program position.  After calibration, send a known good format to the printer to test encoding (see below).  If you receive voids, or it does not encode, move to step 3 to calculate program position manually.

3. To calculate the program position manually, we need to first ensure that the tag meets the Inlay Placement Specification. Read More>>  If it does not, the customer will have to contact the label vendor for specifications on the inlay (a,x,y, read and write powers), but we can’t guarantee it will function as it is not tested.  See below for example:

User-added image

Step One: Measure the distance from the trailing edge of the inlay (portion of inlay closest to trailing gap or mark) to the trailing edge of the gap or mark (see photo to right).  Measure this in millimeters.

Step Two: Subtract the measured distance from the provided tag guide line x value.  Example: If the measured distance of the sample tag’s x value to the right is 11mm and the provided tag guideline for x is 7mm as above, then your equation would be

7-11=-4, making your actual x value F4mm.  

**Hint: If your value is positive after the equation, then the ^RS command will have a B value.  If the value is negative, then your ^RS command will have a F value.

Step Three: Create a program position command including your read and write powers from the tag guidelines.  If we were using the guidelines from above and our actual x value is B8, the follow command needs to be sent to the printer to set the program position and read and write powers.


**This should set the proper read at write power as well the proper program position for the tag being used**

User-added image


4. After this, send a known good tag format such as below.  Ensure that there is no voiding and that only the tag quantity specified is printed/encoded.


5. While printing, please make sure you keep the Media Cover closed.  It keeps the dust out and prevents RF from leaking out.

6. If the steps above do not work, check to make sure the printer is at the current firmware level (Printer Firmware and Reader   Firmware). Print a configuration label to check this.. Reader firmware is listed under RFID VERSION on the Config Label.  New updates can be found at zebra website.  Note: If reader firmware is not listed on the website no update is available or it has been built into the printer's firmware.  Trouble installing the firmware for your printer?  When installing firmware into your printer.  PLEASE BE PATIENT.  If you shut off the printer in the middle of the download the printer will not receive the entire application.  After you download the Reader firmware you need cycle the power to the printer for 3 seconds.

7. Check Environment for Interference. External Reader/Antenna, Radio Waves, Electrical Power Cables, Cordless Phones   etc.

If you have technical questions contact Technical Support Read More>>


+ Product Codes

  • RP4T RFID Printers
  • RP4T RFID Printers