ThingMagic Micro Hardware - Manual (Page 55)

Regulatory Support
A D I V I S I O N O F T R I M B L E
50 Functionality of the Micro
Sets the PLL Frequency Setting to the first entry in the hop table, even if the RF is off.
Selects the transmit filter, if applicable.
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 Micro has commands that allow the
transmit frequency to be set manually.
Frequency Units
All frequencies in the Micro 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 Micro has 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.