Module Integration Manual
Page 12 of 18
Interrogator RF Board (400.00152.xxxx)
7
R
EGIONAL
S
ETTINGS
The following are factory settings required for delivery of products in different regions. The
settings require two levels of password access (factory and distributor).
Only distributors that
have been trained for professional installation will have access to the distributor settings
to allocate the appropriate region for installation.
ABS_MIN_FREQ & ABS_MAX_FREQ
The INTERROGATOR RF BOARD supports regional settings to limit the allowed transmission
frequencies: These settings default to 425MHz and 445MHz.
In CE compliant (EN300220) modes the limits are 433,266MHz to 434,554MHz. Note that CCC
allows two bands.
MAX_PPS
The INTERROGATOR RF BOARD supports four RF Port specific settings to limit the fine power
adjust setting such that the transmit power cannot exceed a predetermined limit. For standard
products these settings are factory adjusted to limit the conducted port power to +10dBm,
although the losses in the TX filter consistently limit TX power below 10dBm without adjustment.
For FCC compliance without an approved metallic enclosure, the system has been evaluated
with a MAX_PPS value of 0 (minimum preamplifier gain).
MAX_PA
The INTERROGATOR RF BOARD supports an EEPROM setting to limit TX power downward in
2.2dB increments. With PA=7, the maximum allowed power (as set by PPS) is generated. With
PA=0 the generated power is reduced by 15.4dB. The PA value is dynamically adjusted to
attain a desired receive signal strength between 0 and the regional limit setting. For FCC
compliance without an approved metallic enclosure, the system has been evaluated with a
MAX_PA value of 3. The conducted TX power associated with PA=3 and PPS=0 on the
reference board was evaluated as -
5.5dBm (282μW).
MIN_OFF_TIME, MAX_ON_TIME, and ON_OFF_RATIO
Transmission ON time limits and IDLE time requirements are controlled by three parameters. A
sophisticated algorithm maximizes ON time within a given regulatory setting. The transmitter
can be IDLE (WAITOVER state), FORCED_OFF (WAITING state), or ACTIVE (TXING state). A
state transition from IDLE to ACTIVE occurs on a first transmission. The ACTIVE_TIME is
monitored and at MAX_ON_TIME (1000ms under FCC 15.231(e)), the state transitions to
FORCED_OFF. Another timer monitors the SILENT_TIME since the last transmission ended.
If this SILENT_TIME timer exceeds MIN_OFF_TIME (10000ms in FCC 15.231(e) and 3600ms
under CE 10% duty cycle) and exceeds the product of ACTIVE_TIME * ON_OFF_RATIO (30 in
FCC 15.231(e) and 1 in CE 10% duty cycle), then the state reverts to IDLE.
