Commands
The user can use either the RS-422 or the CAN-FD interface, depending on the variant, to transmit commands to the IMU in ASCII format. This command set is identical across the whole MK2 family. Below is an exhaustive and descriptive list of the available commands.
Remember that, for the RS422 variant, commands must be COBS-encoded and terminated with a 0x00 byte before transmission. Refer to RS422 Frame Decoding & Encoding — COBS if needed.
Enter Configuration State
| Command | IMU State | IMU Response |
|---|---|---|
CONFIG\r\n |
Operating State | IMU switches to Configuration State. |
Exit to Operating State
| Command | IMU State | IMU Response |
|---|---|---|
EXIT\r\n |
Configuration State | IMU switches to Operating State. |
Soft-Reset
| Command | IMU State | IMU Response |
|---|---|---|
RESET\r\n |
All | IMU resets (switches to Startup State, from software). |
Get a Startup Frame
| Command | IMU State | IMU Response |
|---|---|---|
SUF\r\n |
Configuration State | IMU sends a SUF with its current configuration. |
Get an Operating Frame
| Command | IMU State | IMU Response |
|---|---|---|
OF<Frame Type*>\r\n |
Configuration State | IMU performs and transmits an OF. |
Details
Frame Type parameter must be encoded with: R, E, Q, M, G, or D only. For example, to receive a Quaternions Operating Frame from the IMU, send OFQ\r\n.
Change Operating Mode
| Command | IMU State | IMU Response |
|---|---|---|
OM<Operating Mode*>\r\n |
Configuration State | IMU changes its OM. |
Details
Operating Mode parameter must be encoded with: I, L, or M only. For example, to configure the IMU to Medium Speed, send OMM\r\n.
Change Operating Frame Types
| Command | IMU State | IMU Response |
|---|---|---|
EOFT<Frame Type*>\r\n |
Configuration State | IMU enables selected OF type. |
DOFT<Frame Type*>\r\n |
Configuration State | IMU disables selected OF type. |
Details
Frame Type parameter must be encoded using one of the following characters: R, E, Q, M, or G. For example, to enable the Euler Angles frame, send EOFTE\r\n. If the Rotation Matrix frame is no longer needed, send DOFTM\r\n.
Change Dynamic Range of Gyroscopes
| Command | IMU State | IMU Response |
|---|---|---|
DRG<Range*>\r\n |
Configuration State | Updates gyroscopes DR. |
Details
Range parameter must be encoded with: 0125, 0250, 0500, 1000, 2000 or 4000 only. For example, to configure gyroscopes with a DR of 250°/sec, send DRG0250\r\n. This command targets the MEMS gyroscopes; on the MK2E2, the optical gyroscope's fixed range is unaffected.
Change Dynamic Range of Accelerometers
| Command | IMU State | IMU Response |
|---|---|---|
DRA<Range*>\r\n |
Configuration State | Updates accelerometers DR. |
Details
Range parameter must be encoded with: 02, 04, 08 or 16 only. For example, to configure accelerometers with a DR of 4g, send DRA04\r\n.
Change Dynamic Range of Inclinometers
| Command | IMU State | IMU Response |
|---|---|---|
DRI<Range*>\r\n |
Configuration State | Updates inclinometer DR. |
Details
Range parameter must be encoded with: 0.5, 1.0, 2.0 or 3.0 only. For example, to configure inclinometer with a DR of 1g, send DRI1.0\r\n.
Change Misalignment Correction Status
| Command | IMU State | IMU Response |
|---|---|---|
EMCORR\r\n |
Configuration State | IMU enables the misalignment correction. |
DMCORR\r\n |
Configuration State | IMU disables the misalignment correction. |
Write User Calibration Register, AHRS & Filters Configurations
| Command | IMU State | IMU Response |
|---|---|---|
WR<Reg*><Value*>\r\n |
Configuration State | Updates specified register. |
Details
Reg parameter must be encoded using one of the following three-character codes: GXB, GYB, GZB, AXB, AYB, AZB, IXB, IYB, MXB, MYB, MZB, MXX, MYX, MZX, MXY, MYY, MZY, MXZ, MYZ, MZZ, FCO, FHS, FRT, FGA, FAR, FMR, GFI, GLP, GHP, AFI, ALP, or AHP — plus GOB on the MK2E2 only, for the Optical Gyroscope Z Bias.
Details
Value parameter must be encoded as exactly 8 hexadecimal characters following the type of the register such as 32-bit floating-point value (float32) for calibration registers and FGA, FAR, FMR, or unsigned 32-bit for the rest. For example, to configure the user gyroscope x-axis bias with an offset of 1.0, send WRGXB3F800000\r\n. Another example, to configure the fusion heading source with the internal magnetometer which is 1, send WRFHS00000001\r\n.
Save Current Configuration to Flash Memory
| Command | IMU State | IMU Response |
|---|---|---|
SAVE\r\n |
Configuration State | IMU saves its current configuration. |
Restore to Factory Settings
| Command | IMU State | IMU Response |
|---|---|---|
REFS\r\n |
Configuration State | IMU is reset to factory settings. |
Response to a Recognized Command
When a recognized command is executed while the IMU is in Configuration State, the following commands indicate successful or failed execution by sending a human-readable ASCII message terminated by \r\n: CONFIG, OM, EOFT, DEOFT, EMCORR, DMCORR, WR, DRG, DRA, DRI, SAVE, and REFS (only if failed for the latter).
Undefined Command
When a command is not recognized or incorrectly formatted in Configuration State, the IMU responds with a human-readable ASCII error message terminated by \r\n. A message not recognized in Operating State will simply be ignored without any response.