Siemens SIMATIC RF662A Operating Instructions Manual page 24

Maximum read/write ranges
Maximum write ranges
The antenna requires more power for writing than for reading data. When writing, the
maximum range reduces by approximately 30% - 50% compared with the read range,
depending on the transponder used.
24
Operating Instructions, 12/2022, C79000-G8976-C684-01
SIMATIC RF662A