3DM
®
-GX5-35
DCP Manual
7.5
Creating Fixed Data Packet Format
The MIP packet structure and protocol provides a great deal of flexibility to the user for creating a
custom data stream. It does this by allowing selectable data fields and individual data rates for each
field. The side effect of this feature is that packets vary in size depending on what data is being
delivered in any particular time frame. For example, if acceleration data is configured for 100 Hz and
magnetometer data is configured for 25 Hz, every fourth packet is larger than the previous three
because of the additional magnetometer data. In some applications, this is undesirable and there may
be a requirement for a fixed packet structure so that each data packet is exactly the same. A fixed
packet structure allows you to find data fields by fixed offsets rather than parsing the packet for each
field.
A fixed packet structure is easily achieved with MIP packet protocol by simply making sure the data rate
for each data quantity is the same. The order of the data fields in the packet reflect the order of the
fields in the
command and thus are completely under the control of the user. Once an
acceptable data packet structure is determined, and all the rates are set to the same decimation, use
the “Save current settings as startup settings” function selector in the message format command, and
that format will be saved and used automatically on subsequent device startups.
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