To upgrade the SLED:
Download the file: https://www.zebra.com/us/en/support-downloads/software/firmware/rfd40-firmware.html
...
Place the DAT file in the /sdcard/Download folder on the device
Use the 123RFID app
Select the Menu in upper left corner and select Firmware update
Click the Update firmware button
It should update the firmware on the sled and restart the sled
