EVK-M8BZOE User Guide
UBX-17053592 - R03
Early Production Information
Testing Super-E mode
Page 16 of 33
5
Testing Super-E mode
This section contains a brief description of main configuration options for optimizing Super-E mode performance
and power consumption using the Messages view of the u-center evaluation software. Refer to the ZOE-M8B Data
Sheet [1], ZOE-M8B System Integration Manual [2] and
u-blox 8 / u-blox M8 Receiver Description including Protocol
Specification
[3] for full descriptions of all available configuration options.
5.1
Power Mode Setup message UBX-CFG-PMS
Power Mode Setup message UBX-CFG-PMS shown in Figure 4 is used to select the power mode. Continuous or
Super-E mode can be selected. There are three predefined power mode setups for Super-E mode including 1 Hz
(default), 2 Hz and 4 Hz update rates. The 1 Hz update rate is a good compromise between position accuracy vs.
power consumption. For demanding applications, 2 Hz update rate provides high performance at some
compromise in power consumption.
For lowest power consumption, Super-E mode supports continuous tracking with update periods up to 10 s. To
set update periods longer than 1 s, select default Super-E mode (1 Hz) and use Extended Power Management
message UBX-CFG-PM2 to set the update period.
u-blox recommends using the predefined power mode settings for Super-E mode, except where users have
very specific power saving requirements.
When selecting a mode using CFG-PMS, always save the configuration by checking the “save
configuration” box in u-center, otherwise the configuration will be lost.
Figure 4: Power Mode Setup message UBX-CFG-PMS. Super-E mode with a desired update rate (1 Hz, 2 Hz or 4 Hz) can be selected
with Options 3(default)-5. Options 0-1 are for Continuous mode settings.
5.2
Extended Power Management message UBX-CFG-PM2
Extended Power Management message UBX-CFG-PM2 shown in Figure 5 offers additional options for Super-E
configuration.
Update periods longer than 1 s are set with the field updatePeriod. The field is automatically set by UBX-CFG-PMS
message for 1-4 Hz update rates, but needs to be adjusted for longer update periods. For example, for 3 s update
period set updatePeriod field to 3000 ms. The maximum value for updatePeriod is 10000 ms , i.e., 10 s.
At start-up, the receiver runs at full power and decodes satellite data (ephemeris, almanac). This initial acquisition
period is by default 300 s to enable receiver to find a sufficient number of satellites also under weak-signal
conditions. If needed, the initial acquisition period can be adjusted with the minAcqTime field given in seconds.
The initial acquisition period can be reduced or even removed if AssistNow
TM
service is used to provide the satellite
information for the receiver. Use of AssistNow
TM
improves receiver performance and reduces power consumption
and is strongly recommended with Super-E mode.
