FAQ

 

 

 

INERTIAL SYSTEMS

How can I make sure that my AHRS / INS is in specification?

There is a standard procedure, a User Acceptance Test (UATR). This procedure must be done onshore with the unit in static condition (office/workshop/test bench). However it doesn't require any metrological tool.  In case you are not sure about this process, include the recorded data and settings file for the concerned unit in an email to support@ixblue.com. 
 

Is the AHRS \ INS compatible with my ____ input or output protocol?

The AHRS and INS units made by IXBLUE accept and output a wide range of protocols. A full list and description of these protocols can be found in the user manual document named INTERFACE LIBRARY. This document includes a description of each input and output protocol.
 

How accurate must my manual Latitude and manual speed setting be?

The latitude, along with the speed, is the most important input component in setting up OCTANS to operate correctly. In order to be in the specification, the manual latitude should be entered to within 0,5 degree. For example if you operate at 42.2 degrees, you must enter between 41.7 and 42.7 degrees in order for the unit performance to meet the specifications. The speed information should be set with an accuracy of ±1.5 knots. 
 

I get an "Output Full" message. What does it mean?

This message means the Data Output settings for the serial output are not correct.  
Often the output frequency is too high or the baudrate is too low in combination with the selected protocol value.
 

What is the latency on iXblue AHRS and INS products?

In general timing parameters are as follows (for details, refer to product specifications)
Latency:
2.35 ms on all serial ports
2.95 ms on Ethernet high priority port
< 5 ms on all other Ethernet ports
Jitter :
< 200 μs on all serial ports
< 400 μs on Ethernet high priority port
< 800 μs on all other Ethernet ports
 

How to retrieve the IP address of an AHRS / INS?

Factory default IP address is 192.168.36.1XX, with XX being the last two numbers of the serial number. If the IP address has been changed and is not known, the following steps shall be followed:
Connect the unit to the PC with repeater serial cable.
Open a hyper terminal window
Connect to the unit using the following configuration:
Baudrate: 19200
Parity: none
Stop bit: 1
Restart the unit
The IP address of the unit will be displayed on the screen during the boot up sequence.
 

What is the power consumption of an AHRS / INS?

iXblue AHRS / INS are known for the low power consumption which is below 25 Watts. Please check the spec sheet for each individual system.
 

I connect my AHRS to a GPS. Which messages should be used?

An AHRS needs Latitude and speed information to give the most accurate data. The information can be set manually in the AHRS, but when connected to a GPS the $GPGGA and $GPVTG messages are recommended. If the AHRS can be time synchronized, the $GPZDA or $UTC message can be configured. A PPS pulse is optional.
 

I connect my INS to a GPS. Which messages should be used?

An INS needs position info to be able to align itself. The $GPGGA message is recommended. It is also advised to add the $GPGST string which gives the standard deviation of the position. If the $GPGST message is not supplied, the INS will use the quality indicator in the telegram (which is a less accurate and robust option). For time synchronization, $GPZDA or UTC timetag message is required. When precise time synchronization is need, PPS shall be supplied to the INS. These Input data should be sent at 1Hz.
 

Can I send USBL data to my INS in a GGA format?

No, this should not be performed as it may affect system performances. Contact support for more details.
 

How accurate must my (GPS) leverarm be?

It is recommended to use lever arms 10x more accurate than the sensor measurement accuracy. For example, within 10cm for a 1m accurate GPS and within 1cm for a 10cm accurate GPS. This will ensure your lever arms will not affect the performance of your system.