LORD 3DM-GX5-35, Руководство пользователя

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3DM
®
-GX5-35
DCP Manual
4.2.5 IMU Message Format (0x0C, 0x08)
Description
Set, read, or save the format of the IMU message packet. This command sets the format
for the IMU data packet when in standard mode. The resulting data messages will main-
tain the order of descriptors sent in the command. The command has a function selector
and a descriptor array as parameters.
Possible Function Selector Values:
0x01 – Use new settings
0x02 – Read back current settings.
0x03 – Save current settings as startup settings
0x04 – Load saved startup settings
0x05 – Reset to factory default settings
The rate decimation field is calculated as follows for IMU messages:
Rate Decimation = IMU Base Rate / Desired Data Rate
You should always retrieve the Base Rate from the Get IMU Data Base Rate command
for computing the desired rate decimation. Base rates vary from device to device. The
IMU base rate for the 3DM-GX5 is 500.
The device checks that all descriptors are valid prior to executing this command. If any of
the descriptors are invalid for the IMU descriptor set, a NACK will be returned and the mes-
sage format will be unchanged. The descriptor array only needs to be provided if the func-
tion selector is = 1 (Use new settings). For all other functions it may be empty (Number of
Descriptors = 0).
Figure 1 -
Field Format Field Length
Field
Descriptor
Field Data
Command 4 + 3*N 0x08
U8 – Function Selector
U8 – Number of Descriptors (N)
N*(U8 – Descriptor, U16 - Rate Decimation)
Reply Field 1:
ACK/ NACK
0x04 0xF1
U8 - echo the command byte
U8 - error code (0: ACK, non-zero: NACK)
Reply Field 2 :
Function = 2
3 + 3*N 0x80
U8 – Number of Descriptors (N)
N*(U8 – Descriptor, U16 - Rate Decimation)
Example
MIP Packet Header Command/Reply Fields Checksum
Sync1 Sync2
Desc.
Set
Payload
Length
Field
Length
Field
Desc.
Field Data MSB LSB
Command:
IMU Message
0x75 0x65 0x0C 0x0A 0x0A 0x08
Function: 0x01
Desc count: 0x02
0x22 0xA0
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