C6000 Handheld Computer|| change model...

Failure to read ultrahigh-frequency (UHF) tags happens more frequent than to read high-frequency (HF) and low-frequency (LF) tags, since UHF has a longer read range and utilizes a different means of tag-reader communication.
In UHF RFID systems, there can be null spots or dead zones in the read field in which tags cannot be energized. Please properly place the tags or move your reader so that all tags can be read.