ThingMagic M5e-Compact - Manual (Page 32)

Frequency Setting
32 Functionality of the Embedded Modules
Frequency Setting
The modules have a PLL synthesizer that sets the modulation frequency to the desired
value. Whenever the frequency is changed, the module must first power off the
modulation, change the frequency, and then turn on the modulation again. Since this can
take several milliseconds, it is possible that tags are powered off during a frequency hop.
In addition to setting the default regional settings, the modules have commands that allow
the transmit frequency to be set manually.
Frequency Units
All frequencies in the Mercury embedded products are expressed in kHz using unsigned
32-bit integers. For instance, a carrier frequency of 915 MHz is expressed as 915000
kHz.
The PLL is set automatically to the closest frequency - based on the minimum frequency
quantization for the current region - that matches the specified value. The Mercury
embedded modules have an absolute minimum quantization of 25 kHz. Each region also
has a minimum quantization based on regulatory specifications, which may be greater.
The following table details the frequency quantization in kHz for each region setting.
C A U T I O N ! ! !
Use these commands with extreme caution.
It is possible to change the module’s com-
pliance with the regional regulations.