This specification is incomplete and might not be always correct. If you find and error, please notify me.

6.1.2 Important concepts

DSP / UCoM:: Name of the control chip / control board used to control the motor driver.
Sequence Number:: Position of the UCoM board in the CAN-Bus. (boards are chained together)
Flash ID:: ID of the UCoM board that is choosen while flashing the bootloader.
Program ID:: Checksum of the firmware that is transmitted over CAN.
Exloader:: Name of the bootloader that executes the firmware.

6.1.3 Implementation Notes

The relevant files for CAN support in MCA/ARMAR are:


 mca2.4/libraries/hardware/UseSocketCAN.h
 mca2.4/projects/armar3/action/hardware/

6.1.4 Message ID encoding

The type of function is encoded in the message id of the CAN frame in the following way:


+--------+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
|Bit     | 15 | 14 | 13 | 12 | 11 | 10 |  9 | 8  |  7 |  6 |  5 |  4 |  3 |  2 |  1 |
+--------+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
|Meaning |            Function Number            |           Sequence Number        |
+--------+---------------------------------------+----------------------------------+

msg_id = ((id & 0x001f) | ((fctn & 0x003f) << 6));

When the sender of the CAN-Frame is the PC, the Sequence Number denotes the recipient. When the sender of the CAN-Frame is a DSP, the Sequence Number denotes the UCoM board.

6.1.5 Function IDs

Name	Number	Sender
PC_RESET	0	PC
PC_XRESET	1	PC
DSP_ERROR	2	DSP
DSP_INITACK	3	DSP
DSP_PROGFINISHED	4	DSP
DSP_INFO	5	DSP
DSP_READY	6	DSP
PC_SETSTATUS	7	PC
PC_INFO	8	PC
PC_REPORT	9	PC
PC_INIT	10	PC
PC_PROG	11	PC
PC_START	12	PC
MCA_PC_CI	13	PC
MCA_DSP_SO	14	DSP
MCA_PC_PAR	15	PC
DSP_REPORT0	16	DSP
DSP_REPORT1	17	DSP
DSP_REPORT2	18	DSP
DSP_REPORT3	19	DSP
MCA_DSP_READY	20	DSP
MCA_PC_START	21	PC
MCA_DUMP_IO_DESCRIPTION	22	PC / DSP
MCA_DUMP_CI	23	PC
MCA_ADMIN_DATA	24	PC / DSP
MCA_DEBUG_MSG	25	DSP
MCA_ALIVE	26	PC / DSP
MCA_DSP_CI	27	DSP

6.1.6 Function descriptions

6.1.6.1 PC_RESET

Meaning:: Reset UCoM boards.
Data:: No data.
Expected response:: UCoMs respond with DSP_REPORT0 - DSP_REPORT3

6.1.6.2 PC_XRESET

Meaning:: Special reset, used when updating the firmware.
Data:: No data.
Expected response:: No response.

6.1.6.3 DSP_ERROR

Meaning:: Send error code to PC.
Data:: 1 byte DSP error codes.
Response:: None.

6.1.6.4 DSP_INITACK

Meaning:: Acknowledge initialisation request with sequence id.
Data:: 1 byte DSP sequence id.
Response:: None.

6.1.6.5 DSP_PROGFINISHED

Meaning:: Programming firmware finished.
Data:: None.
Response:: None.

6.1.6.6 DSP_READY

Meaning:: DSP signals it is ready to receive more program data. (used while programming for flow control)
Data:: None.
Response:: None.

6.1.6.7 PC_SETSTATUS

Meaning:: Set status of target DSP.
Data:: 2 Bytes: new_state = (old_state & ~bit-mask) | 2nd_byte


+-------------+------+------+------+------+------+------+------+------+
| Byte - Bit  |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
+=============+======+======+======+======+======+======+======+======+
|     0       |                bit-mask for second byte               |
+-------------+------+------+------+------+------+------+------+------+
|     1       |MSTART|ASTART|MCARUN|EXLRUN| INIT | PROG |OPINIT|IPINIT|
+-------------+------+------+------+------+------+------+------+------+

6.1.6.8 PC_INFO

Meaning:: Request information about the ucom board.
Data:: None.
Response:: DSP_INFO with data containing information about the DSP.

6.1.6.9 DSP_INFO

Meaning:: DSP sends information about state/options to PC.
Data:: Multiple packages.

DSP Info (1 package, 8 Bytes)


+-------------+------+------+------+------+------+------+------+------+
| Byte - Bit  |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
+=============+======+======+======+======+======+======+======+======+
|     0       |                1. Byte Flash Number                   |
+-------------+------+------+------+------+------+------+------+------+
|     1       |                2. Byte Flash Number                   |
+-------------+------+------+------+------+------+------+------+------+
|     2       |                  Sequence Number                      |
+-------------+------+------+------+------+------+------+------+------+
|     3       |MSTART|ASTART|MCARUN|EXLRUN| INIT | PROG |OPINIT|IPINIT|
+-------------+------+------+------+------+------+------+------+------+
|     4       |                1. Byte Program ID                     |
+-------------+------+------+------+------+------+------+------+------+
|     5       |                2. Byte Program ID                     |
+-------------+------+------+------+------+------+------+------+------+
|     6       |                1. Byte Program Flash Date             |
+-------------+------+------+------+------+------+------+------+------+
|     7       |                2. Byte Program Flash Date             |
+-------------+------+------+------+------+------+------+------+------+

MSTART:: MCA is started
ASTART:: Autostart is enabled
MCARUN:: MCA is running
EXLRUN:: Bootloader is running
INIT:: UCoM is initialized
PROG:: Programming is enabled
OPINT:: State of init-pin (outgoing)
IPINT:: State of init-pin (incoming)

DSP description (multiple packages) String transmission packages containing the description

Response:: None.

6.1.6.10 PC_REPORT

Meaning:: List all DSPs that are listening over CAN-Bus. (only used for debugging) It is similar to the PC_RESET command, only it will not actually reset the DSP.
Data:: None.
Response:: DSPs should answer with DSP_REPORT0 - DSP_REPORT3.

6.1.6.11 PC_INIT

Meaning:: Initialize the target DSP.
Data:: None.
Response:: DSP should answer with DSP_INITACK.

6.1.6.12 PC_PROG

Meaning:: Start a cycle to transmit program data. (there are 2 cycles needed)
Data:: 8 Packages each 8byte payload of program data.
Response:: None.

6.1.6.13 PC_START

6.1.6.14 MCA_PC_CI

6.1.6.15 MCA_DSP_SO

6.1.6.16 MCA_PC_PAR

6.1.6.17 DSP_REPORT0 - DSP_REPORT3

Meaning:: Answer to reset command.
Data:: 1 byte UCoM id
Response:: None.

6.1.6.18 MCA_DSP_READY

6.1.6.19 MCA_PC_START

6.1.6.20 MCA_DUMP_IO_DESCRIPTION

When send by PC:

Meaning:: Dump description of CI/SO/PARA
Data:: None.
Response:: Target DSP sends MCA_DUMP_IO_DESCRIPTION messages.

When send by DSP:

Meaning:: Flag for packages that contain edge/parameter descriptions.
Data:: Multiple Packages with the same flag, number of descriptions for each type is contained in first package.

CI/SO/PAR dimensions (1 package)


+------+-----------------------+
| Byte |  Meaning              |
+======+=======================+
|  0   | 1. Byte CI dimension  |
+------+-----------------------+
|  1   | 2. Byte CI dimension  |
+------+-----------------------+
|  2   | 1. Byte SO dimension  |
+------+-----------------------+
|  3   | 2. Byte SO dimension  |
+------+-----------------------+
|  4   | 1. Byte PAR dimension |
+------+-----------------------+
|  5   | 2. Byte PAR dimension |
+------+-----------------------+

DSP description (multiple packages)

String transmission packages containing the description of the DSP.
CI descriptions (multiple packages)

For each CI one string transmitted by string transmission packages.
SO descriptions (multiple packages)

For each SO one string transmitted by string transmission packages.
PARAM descriptions (multiple packages)

For each PARAM one string transmitted by string transmission packages.

Response:: None

6.1.6.21 MCA_DUMP_CI

Meaning:: Dump initial values that should be send as CI to the DSP.
Data:: None
Response:: DSP should answer with MCA_DSP_CI packages.

6.1.6.22 MCA_DSP_CI

Meaning:: Transmit initial values for PC to send over CAN as CI.
Data:: CI-dimension / 3 packages containing each 3 initial values.
Response:: None.

6.1.6.23 MCA_ADMIN_DATA

When send by the PC: Meaning: ~ Set state of MCA module on DSP.

When send by the DSP: Meaning: ~ Current state of the DSP.

(Data format is the same for sending an receiving)

Data:: For all targetet DSPs each being 0 or 1.


+------+-----------------------+
| Byte |  Meaning              |
+======+=======================+
|  0   | 1. run state          |
+------+-----------------------+
|  1   | 2. active state       |
+------+-----------------------+
|  2   | 2. debug state        |
+------+-----------------------+
|  3   | 2. global debug state |
+------+-----------------------+

Response:: None.

6.1.6.24 MCA_DEBUG_MSG

Meaning:: DSP sends debug message to PC.
Data:: String transmission.
Response:: None

6.1.6.25 MCA_ALIVE

When send from PC: Meaning: ~ PC is still alive. (should be send all 500ms to all DSPs) Data: ~ None Response: ~ None

When send from DSP: Meaning: ~ DSP is still alive. (should be received all 1000ms) Data: ~ None. Respone: ~ None.

6.2 String transmission packages

Strings are transmitted in the following way:

First Package, data frame format:


+------+-----------------------+
| Byte |  Meaning              |
+======+=======================+
|  0   | 1. Byte num msgs      |
+------+-----------------------+
|  1   | 2. Byte num msgs      |
+------+-----------------------+

Rest of packages, data frame format:


+------+-----------------------+
| Byte |  Meaning              |
+======+=======================+
|  0   | string data byte      |
+------+-----------------------+
| ...  |         ...           |
+------+-----------------------+
| DLC  | string data byte      |
+------+-----------------------+

6.3 SO/CI/PAR transmission packages

For the n-th package:


+------+-----------------------+
| Byte |  Meaning              |
+======+=======================+
|  0   | 1. Byte buffer offset |
+------+-----------------------+
|  1   | 2. Byte buffer offset |
+------+-----------------------+
|  2   | 1. Byte buf[n]        |
+------+-----------------------+
|  3   | 2. Byte buf[n]        |
+------+-----------------------+
|  4   | 1. Byte buf[n+1]      |
+------+-----------------------+
|  5   | 2. Byte buf[n+1]      |
+------+-----------------------+
|  6   | 1. Byte buf[n+2]      |
+------+-----------------------+
|  7   | 2. Byte buf[n+2]      |
+------+-----------------------+

6.4 DSP Error codes

Name	Number	Cause
DSP_ERROR_CHECKSUM	1	Checksum error.
DSP_ERROR_MEM_PROTECTED	2	Memory area disabled or protected.
DSP_ERROR_FLASH	3	Error while flashing.
DSP_ERROR_OVERRUN	4	Buffer overrun
DSP_ERROR_DATA	5	Invalid dataheader
DSP_ERROR_CAN_TRANSMIT	6	CAN transmission error.
DSP_ERROR_CAN_RECEIVE	7	CAN receive error.
DSP_ERROR_CAN_OVERRUN	8	CAN buffer overrun.
DSP_ERROR_REINIT	9	Previous init request was not acknowledged.
DSP_ERROR_EXLOAD_CYCLE	10	ExLoading failed.
DSP_ERROR_AUTOSTART_FORBIDDEN	11	Autostart forbidden. No application or exloader in program flash.

Karlsruhe Head Documentation

6 Specification

6.1 UCOM CAN-Bus Functions

6.1.1 Warning