ThingMagic M5e-Compact - Manual (Page 41)

Power Management
Functionality of the Embedded Modules 41
Low Power Mode
This mode minimizes power consumption and optimizes thermal characteristics without
compromising performance in many, but not all, applications. Low power mode uses less
DC power than High Performance mode at all RF transmit levels. It consumes up to 7.5W
(6.5 typical) at a transmit level of +30dBm, decreasing to 3.5W at transmit levels of
+20dBm and below. Low Power mode should be selected for most applications,
including:
All tag printer applications (where tags are placed very close to the antenna)
All applications where the Read and Write transmit power levels are between +27 and
+30 dBm.
If the application does not meet the above criteria, the optimum mode can be determined
by considering a combination of conditions: expected transmit on/off duty cycle, expected
ambient temperature, and whether the reader will be operating in a noisy RF
environment.
The following table provides recommendations on which Power Mode to use for various
application environments: printer, few readers (non-dense reader environment), many
readers (dense reader environment); based on the required RF Power level.
Power Mode per Operational Environment and RF Power Setting
Thermal characteristics are another differentiator between the two modes. Low Power
Mode allows the module to operate in a 60
o
C ambient environment, regardless of how
continuously the module is transmitting. High Performance mode is only recommended in
a 60
o
C environment if the module is actively transmitting less than 50% of the time. If the
module is transmitting more often than this, a lower maximum ambient temperature must
be maintained as show in the following table:
RF Transmit Power 5-18 dBm 18-27dBm 27-30 dBm
Low Power Mode • Printer
• Few Readers
• Printer • Printer
• Few Readers
• Many Readers
High Performance Mode • Many Readers • Few Readers
• Many Readers
•