OS command

Overview

The OS command is a standard way of triggering actions or services on the drive by which cannot be adapted to a single SDO upload/download.

The following commands are currently available:

  • Command 0: Encoder register communication

  • Command 1: iC-MU calibration mode

  • Command 2: Open Loop Field Mode (OLFM)

  • Command 3: HRD streaming

  • Command 4: Motor phase order detection

  • Command 5: Commutation offset detection

  • Command 6: Open phase detection

  • Command 7: Pole pair detection

  • Command 8: Phase resistance measurement

  • Command 9: Phase inductance measurement

  • Command 10: Torque constant measurement

Usage

The OS command feature can be operated with the objects 0x1023 (OS command) and 0x1024 (OS command mode).

0x1023: OS command

Select the command that should be used and start it by writing the desired value in subindex 1.

The status can be read in subindex 2.

The response can be fetched in subindex 3, it includes the status as written in subindex 2.

Note

To calculate the progress, please subtract 100 from the value of 0x1023:2.

Subindex Description Data Type Value
1 Command OCTET_STRING Byte 0:OS command ID
Byte 1-7:Service request data

A write access to the subindex will execute the command
2 Status UNSIGNED8 0: last command completed, no errors, no response data.
1: last command completed, no errors, response data available
2: last command completed, error, no response data
3: last command completed, error, response data available
100-200: command executing with percentage (100 = 0%, 200 = 100%)
255: command executing (if percentage display is not supported)
3 Response OCTET_STRING Byte 0: identical with subindex 2
Byte 1: unused
Byte 2-7: Service response data

Details

  • Subindex 1 can’t be written until the command is finished and the response is read in subindex 3. If a command is written in that case anyway, it will be ignored and an OsCmdCol error will be raised.

  • The status of the command can be read in Subindex 2 and is also available in the first byte of subindex 3.

Note

It is recommended to read the status from the first byte of subindex 3 instead of subindex 2 because reading subindex 2 when a command is finished will not make subindex 1 writable again. The subindex 3 has to be read at least once after writing, before the next write command can be performed.

  • Both subindex 1 and subindex 3 are octet strings of size 8.

  • Byte 0 of the subindex 1 is used to choose the command that shall be executed.

  • The rest of the bytes are used to specify the parameters of the command, so they are command specific.

  • Byte 0 of the subindex 3 shows the status of the command. Depending on its value the rest of bytes on that subindex differ:

    • If the command is in progress (byte 0 is 100-200 or 255) or completed with no response data (byte 0 is 0 or 2), no other bytes will be set.

    • If the command is completed with no errors and with response data (byte 0 is 1), command specific bytes will be set starting at byte 2.

    • If the command is completed with errors and with response data (byte 0 is 3), byte 2 will be the OS error code (see below) and command specific bytes will be set starting at byte 3.

The following table shows all the valid responses (subindex 3) that any OS command might respond with. Grey table cells mean: these bytes are optional.

Description Byte 0
(Status)
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Command in progress (with percentage) 100 - 200
Command in progress (without percentage) 255
Command completed without errors and without response 0
Command completed without errors and with response 1 Data Data Data Data Data Data
Command completed with error and without response 2
Command completed with error and response 3 OS error code
(see below)
Data Data Data Data Data

OS error code

Indicates the reason of an error when the current command is completed with errors and with response data (status is 3).

Note

Error codes 0 - 8 are command specific, while error codes 251 - 254 are general error codes.

The command-specific OS error codes will be explained in detail in the corresponding section.

General OS error codes:

  • Unsupported command: the command ID received doesn’t exist.

  • Command timeout: A request to execute an OS command or to abort it was not acknowledged by any downstream service after 5s.

  • Command aborted: The abort action triggered by the user was successful.

  • Command not allowed: Certain commands can execute only under certain conditions (in a specific operation mode for example). This error code will be used to signal that these conditions are not met.

OS Command #
0 1 2 3 4 5 6 7 8 9 10
OS error code 0 Initialization error Open terminal A Current ampl. error
OS error code 1 Streaming error Open terminal B
OS error code 2 Duration value Open terminal C
OS error code 3 Data index value Open FET A high
OS error code 4 Action value Open FET A low
OS error code 5 Open FET B high
OS error code 6 Open FET B low
OS error code 7 Open FET C high
OS error code 8 Open FET C low
(reserved for future use)
OS error code 251 Command not allowed
OS error code 252 Command aborted
OS error code 253 Command timeout
OS error code 254 Unsupported command

0x1024: OS command mode

This object is only used to abort the current command when value 0x03 is written. Otherwise (value 0x00 is written as a default) the next command is executed immediately.

Value Description
0x00 Execute the next command immediately (default)
0x03 Abort the current command and all commands in the buffer

Details

  • This object is write-only.

  • Writing 0 to this object will enable “Execute the next command immediately”, which is the default mode. In this mode, new OS commands will be executed as described above.

  • Writing 3 to this object will abort the currently executing command. Once the command is aborted successfully, the status “last command completed, error, response data available” (3) will be sent by the slave, and the OS error code (which will be explained in more detail later) in byte 2 of the response will signal the command abortion. If there is no command in progress, this write operation will be ignored.

OS command behavior

The drive only accepts OS commands when the OS command state is idle, which means that the last command was completed and the response was read from 0x1023:3. Otherwise the OS command will be ignored, and the drive will enter the Fault CiA402 state (error report description will be OsCmdCol, which stands for OS command collision).

If subindex 0x1024:0 is not 0, the OS command will be ignored and discarded and no error will be raised.

Whenever an OS command is sent, the status will change from 0, 1, 2 or 3 to 255 immediately to ensure that the correct response is received.

At any point while a command is in progress, that command can be aborted writing 3 to the object 0x1024.

Flowchart of the Command

../../../../../_images/os_command_simple.png

Available commands

Command 0: Encoder register communication

This command is used for reading or writing registers from a BiSS encoder.

Note

For more information about how BiSS register communication works, please refer to the official BiSS-C Interface Protocol Description.

Command request

The values in 0x1023:1 for this command are as follows:

Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 0
1 Encoder connector
2 Slave address / ID (0) ⌝R/W
3 Register address
4 Register write value

Explanation of the parameters:

  • Encoder connector: select the target encoder for the command:

    Value

    0x2100 subindex

    0

    1 (Sensor port 1)

    1

    2 (Sensor port 2)

    2

    3 (Sensor port 3)

    8

    9 (Sensor port 9)

  • Slave address: selects the address of the slave to read (BiSS protocol level). This value must always be 0.

  • ¬R/W: Selects the direction of the command: 0 for reading a register, 1 for writing it.

  • Register address: Register to be read/written.

  • Register write value: Value to write to the register. This is only used if the parameter ¬R/W is set to 1.

Command response

Description Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Command in progress (without percentage) 255
Command completed without errors and with response 1 Register value
Command completed with error and response 3 OS error code
  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The register value is the value read/ written from/to the selected register.

  • Status 3: The command has finished unsuccessfully. The error code will be sent, either as a general OS error code or a command-specific OS error code:

OS error code Error name Error description
0 Invalid response There was an error while executing the BiSS register transaction. This can be caused by
  • a too short BiSS timeout,
  • too high BiSS clock frequency or
  • trying to access a register that does not exist
1 Register not allowed The register can’t be read given the current configuration. Currently the only registers that are not allowed to read are the iC-MU I2C registers (range 0x5B-0x6F) in Internal encoder 1 of Circulo if multiturn is disabled. If this happens, it can be avoided by setting the subindex "Status bits active value" to "Status bits ignored".

Example

To write the value 0x08 in register 0x11 of Circulo internal encoder 2, the bytes in 0x1023:1 should be set like this:

Byte

Value

0

0

1

1

2

1

3

0x11

4

0x08

In the terminal the following command can be used:

ethercat download 0x1023 1 0x0811010100 --type int64

Note

This command can only be used with IgH EtherCAT Master for Linux

To fetch the response, the following command should be entered:

ethercat upload 0x1023 3 --type int64

This value should be returned: 0x0000000000080001 (Status 1, with a confirmation of the written register value).

Command 1: iC-MU calibration mode

This command is used to be able to set a particular BiSS mode when using an iC-MU encoder, which is mostly used for iC-MU calibration. The following modes are supported:

  • Configuration mode: the BiSS service reads the encoder normally but it only uses the bits for register communication and discards the rest, so the encoder data is not updated. This also means BisCrc error is not raised while in this mode.

  • Raw mode: The BiSS service reads the encoder assuming it was correctly configured for raw mode. It continues calculating all the encoder data but in addition to that it also average of the raw data and makes it available in object 0x2704 User MISO like this:

    Bit
    31-28 27-14 16-0
    0 Nonius count Master count
  • Standard mode: The BiSS service clocks the encoder normally.

When transitioning from any mode to Configuration mode, the current position is saved. When switching to Raw mode, this saved position will be used as a starting point for the position calculation, because the raw data is relative. This means that the motor should not be moved while in Configuration mode if we plan to switch to Raw mode after.

Command request

Values in 0x1023:1 for this command:

Byte

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

1

1

Mode enable

Encoder connector

Explanation of the parameters:

  • Mode enable: select the iC-MU calibration mode.

    Value

    Mode

    0

    Configuration mode

    1

    Raw mode

    2

    Standard mode

  • Encoder connector: select the target encoder for the command. A value of 0 will select the encoder assigned to Sensor port 1 in 0x2100 Position feedback ports, a value of 1 will select Sensor port 2 and so on.

    Value

    0x2100 subindex

    0

    1 (Sensor port 1)

    1

    2 (Sensor port 2)

    2

    3 (Sensor port 3)

    8

    9 (Sensor port 9)

Command response

Possible responses of this command:

Description Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Command in progress (without percentage) 255
Command completed without errors and without response 0
Command completed with error and without response 2
Command completed with error and response 3 OS error code
  • Status 255: The command is in progress.

  • Status 0: The command was finished successfully.

  • Status 2: The command couldn’t be executed on the sensor. The received Mode enable value is unknown.

  • Status 3: This command doesn’t have any command-specific OS error code, so this status will only happen when a general OS error code occurs.

Example

Configuring raw mode on Circulo Internal encoder 1:

  1. Enable Configuration mode to freeze the current absolute position.

    To change Internal encoder 1 of Circulo to Configuration mode, the bytes in 0x1023:1 need to be set like this:

    Byte

    Value

    0

    1

    1

    0

    In the terminal the following command can be used:

    ethercat download 0x1023 1 0x0001 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    Which should return 0x0000000000000000 (Status 0).

  2. Use OS command 0 to configure the Circulo internal encoder 1 to output raw mode. Check the iC-MU datasheet for more information.

  3. Enable Raw mode.

    To change Internal encoder 1 of Circulo to Raw mode, the bytes in 0x1023:1 need to be set like this:

    Byte

    Value

    0

    1

    1

    1

    In the terminal the following command can be used:

    ethercat download 0x1023 1 0x0101 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    Which should return 0x0000000000000000 (Status 0).

Command 2: Open Loop Field Mode (OLFM)

This command is used to be able to configure the settings of the Open Loop Field Mode (OLFM) profiler. The following configuration can be set by using this OS command:

Parameters related to the profiler of the electrical angle:

  • Starting electrical angle [mrad]

  • Ending electrical angle [mrad]

  • Maximum electrical rotational speed [rad / s]

  • Electrical rotational acceleration [rad / s²]

Parameters related to the profiler of the magnetic field length:

  • Starting length [per thousand rated current]

  • Ending length [per thousand rated current]

  • Increasing length rate [per thousand rated current / s]

Once the configurations of OLFM profiler are set, the user can put the drive in the corresponding OLFM op_mode (The op_mode for OLFM operation is -3), and by enabling the operation the Drive will generate a magnetic field according to the settings of its profiler. More information about this mode can be found in [Missing link].

Command request

Values in 0x1023:1 for this command:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

2

Byte 1

Parameter index

Byte 2

Parameter value [MSB]

Byte 3

Parameter value [MSB-1]

Byte 4

Parameter value [MSB-2]

Byte 5

Parameter value [LSB]

Explanation of the parameters

  • Parameter index: Selects the parameter that shall be configured.

Value

Parameter and units

0

Starting electrical angle [mrad]

1

Ending electrical angle [mrad]

2

Maximum electrical rotational speed [rad / s]

3

Electrical rotational acceleration [rad / s²]

4

Starting length [per thousand rated current]

5

Ending length [per thousand rated current]

6

Increasing length rate [per thousand rated current / s]

  • Parameter value: The value to set the selected parameter to. The maximum size for the value is 32 bits and Byte 5 is the least significant byte (LSB).

Command response

The possible responses of this command:

Description Byte 0
(Status)
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Command in progress (without percentage) 255
Command completed without errors and without response 0
Command completed with error and without response 2
Command completed with error and response 3 OS error code
  • Status 255: The command is in progress.

  • Status 0: The command was finished successfully.

  • Status 2: The command couldn’t be executed. The received Parameter index value is unknown.

  • Status 3: This command doesn’t have any command-specific OS error code (this status will only happen when a general OS error code occurs).

Example

For setting the “Starting electrical angle [mrad]” to 1000, the parameter value should be converted to hexadecimal so that it is easier to split between multiple bytes. In this case, 1000 is 0x3E8.

Then we should set the bytes in 0x1023:1 like this:

Byte

Value

0

2

1

0

2

0

3

0

4

0x03

5

0xE8

In the terminal the following command can be used:

ethercat download 0x1023 1 0xe80300000002 --type int64

To fetch the response, enter the following command:

ethercat upload 0x1023 3 --type int64

Which should return 0x0000000000000000 (Status 0).

Command 3: HRD streaming

This command is used for streaming data into files. The data written to these files is in binary format.

  • Multiple files will be created if necessary, up to a maximum of 5 files.

  • Each of the files will have a maximum size of 8032 bytes

  • The files are named “hr_dataX.bin”, where X is a number starting at 0.

Two actions are supported for this command:

  • Configure stream: all previous HRD files are deleted from the filesystem, and the user configures the duration of the stream and the variable to stream. Deleting files can take up to 5 seconds in the worst case scenario.

  • Start stream: The stream is started with the previously sent configuration.

Command request

The values in 0x1023:1 for this command are as follows:

Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 3
1 - Action
2 Data index
3 Duration in ms [MSB]
4 Duration in ms [LSB]

Explanation of the parameters:

  • Action: select the action to perform.

Value

Action

0

Configure stream

1

Start stream

  • Data index: select the data to be streamed. This value is only used when the selected Action is Configure stream (0).

Value

Data

Description

0

Encoder raw data

Record encoder raw data. The encoder should be set up first with OS command 1.

  • Duration in ms: select the duration in milli-seconds of the stream. This value is only used when the Action is Configure stream (0). The maximum value for this parameter is 10000 ms.

Command response

Description Byte 0
(Status)
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Command in progress (with percentage) 100 - 200
Command in progress (without percentage) 255
Command completed without errors and without response 0
Command completed with error and response 3 OS error code
  • Status 100-200: The command to stream the data to a file (Action is 1) is in progress.

  • Status 255: The command to configure the stream (Action is 0) is in progress.

  • Status 0: The command has finished successfully.

  • Status 3: The command has finished unsuccessfully. The error code will be sent, either as a

OS error code

Error name

Error description

0

Initialization error

The command failed to initialize.

1

Streaming error

Something failed while streaming was in progress.

2

Duration value

The selected Duration value is larger than 10000 ms.

3

Data index value

The selected Data index is unknown.

4

Action value

The selected Action is unknown.

Example

Streaming encoder raw data into a file for 5 s:

  1. Use OS command 0 and OS command 1 to configure the iC-MU to output raw data.

  2. Configure the streaming:

    To configure the stream first we need to convert the duration to hexadecimal so that it is easier to split between multiple bytes. In this case, 5000 is 0x1388.

    The bytes in 0x1023:1 should be:

    Byte

    Value

    0

    3

    1

    0

    2

    0

    3

    0x13

    4

    0x88

    In the terminal the following command can be used:

    ethercat download 0x1023 1 0x8813000003 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    Which should return 0x0000000000000000 (Status 0).

  3. Start the streaming.

    The bytes in 0x1023:1 should be:

    Byte

    Value

    0

    3

    1

    1

    In the terminal the following command can be used:

    ethercat download 0x1023 1 0x0103 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    Which should return 0x0000000000000000 (Status 0).

Command 4: Motor phase order detection

This command is used to be able to detect the order of the motor phases, it is also the first step that is performed during Offset detection. When this command finishes successfully the found value is automatically written to the object 0x2003:5 Motor phases inverted.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically finished. More information about this operation mode can be found in the Diagnostics opmode.

Command request

The values in 0x1023:1 for this command are as follows:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

4

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and with response

1

Motor phase order

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The detected motor phase order is written in byte 2.

    Value

    Motor phase order

    0

    Normal order

    1

    Inverted order

  • Status 3: This command doesn’t have any command-specific OS error code, so this status will only happen when a general OS error code occurs.

Example

To measure the motor phase order of our setup, we would need to:

  1. Switch to diagnostics mode, enter operation enable and disengage the brake if there is one. For details please refer to Diagnostics opmode.

  2. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 4.

    In the terminal the following command can be used:

    ethercat download 0x1023 1 0x04 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    
  • If the Motor phase order is normal, the response would be 0x0000000000000001 (Status 0, Normal motor phase order).

  • If the Motor phase order is inverted, the response would be 0x0000000000010001 (Status 1, Inverted motor phase order).

Command 5: Commutation offset detection

This command is used to measure the commutation angle offset which is the second step in the Offset Detection procedure. The configuration of the procedure is taken from the already existing and previously used commutation offset objects in the object dictionary. When this command finishes successfully the found value is automatically written to the object 0x2001:0 Commutation angle offset, and the object 0x2009:1 State is set to OFFSET_VALID.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically aborted. More information about this operation mode can be found in Diagnostics opmode.

For details about the different methods for Offset detection, refer to Commutation Offset Detection.

Command request

The values in 0x1023:1 for this command are as follows:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

5

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and with response

1

Commutation angle offset [MSB]

Commutation angle offset [LSB]

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The measured angle offset is written in bytes 2 and 3.

  • Status 3: This command doesn’t have any command-specific OS error code, so this status will only happen when a general OS error code occurs.

Example

To measure the commutation angle offset of our setup, we would need to:

  1. Configure the Commutation offset detection parameters in the object 0x2009.

  2. Switch to diagnostics mode, enter operation enable and disengage the brake if necessary. For details please refer to Diagnostics opmode.

  3. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 5. In the terminal the following command can be used:

    ethercat download 0x1023 1 0x05 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    In case the Commutation angle offset is 2035, this would return 0x0000000007F30001 (Status 1, 2035 is 0x7F3 in hexadecimal).

Command 6: Open phase detection

This command is used for detecting if one of the phases is open.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically aborted. For details please refer to Diagnostics opmode.

Command request

The values in 0x1023:1 for this command are as follows:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

6

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and without response

0

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 0: The command was finished successfully, no open motor phase was detected.

  • Status 3: The command was finished unsuccessfully. Either a general OS error code or a command-specific OS error code will be sent.

OS error code

Error name

Error description

0

Open terminal A

Terminal A of the Drive is not connected

1

Open terminal B

Terminal B of the Drive is not connected

2

Open terminal C

Terminal C of the Drive is not connected

3

Open FET A high

Upper FET in leg A of the Drive is not conducting (open circuit fault)

4

Open FET A low

Lower FET in leg A of the Drive is not conducting (open circuit fault)

5

Open FET B high

Upper FET in leg B of the Drive is not conducting (open circuit fault)

6

Open FET B low

Lower FET in leg B of the Drive is not conducting (open circuit fault)

7

Open FET C high

Upper FET in leg C of the Drive is not conducting (open circuit fault)

8

Open FET C low

Lower FET in leg C of the Drive is not conducting (open circuit fault)

Example

To detect if any of the motor phases is open in our setup, we would need to:

  1. Switch to diagnostics mode and enter operation enable. For details please refer to Diagnostics opmode.

  2. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 6. In the terminal the following command can be used:

    ethercat download 0x1023 1 0x06 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

Command 7: Pole pair detection

This command is used to detect the amount of pole pairs that the connected motor has.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically aborted. For details please refer to Diagnostics opmode.

Command request

The values in 0x1023:1 for this command are as follows:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

7

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and with response

1

Number of pole pairs

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The measured number of motor pole pairs is written in byte 2.

  • Status 3: The command was finished unsuccessfully. Either a general OS error code or a command-specific OS error code will be sent.

OS error code

Error name

Error description

0

Current ampl. error

Drive is not able to increase the amplitude of motor phase currents to the required value. This problem can happen due to limited V DC or high motor phase impedances

Example

For measuring the motor phase order:

  1. Switch to diagnostics mode, enter operation enable and disengage the brake if there is one. For details please refer to Diagnostics opmode.

  2. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 7. In the terminal the following command can be used:

ethercat download 0x1023 1 0x07 --type int64

To fetch the response, enter the following command:

ethercat upload 0x1023 3 --type int64

In case the motor has 3 pole pairs, this would return 0x0000000000030001 (Status 1).

Command 8: Phase resistance measurement

This command is used to measure the phase resistance of the motor in mOhm.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically aborted. For details please refer to Diagnostics opmode.

Command request

Values in 0x1023:1 for this command:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

8

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and with response

1

Phase resistance [MSB]

Phase resistance [MSB-1]

Phase resistance [MSB-2]

Phase resistance [LSB]

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The measured motor phase resistance is written in bytes 2, 3, 4 and 5.

  • Status 3: The command was finished unsuccessfully. Either a general OS error code or a command-specific OS error code will be sent.

OS error code

Error name

Error description

0

Current ampl. error

Unable to increase the current amplitude.

Example

To measure the motor phase resistance of our setup, we would need to:

  1. Switch to diagnostics mode, enter operation enable and disengage the brake if there is one. For details please refer to Diagnostics opmode.

  2. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 8. In the terminal the following command can be used:

    ethercat download 0x1023 1 0x08 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    In case the motor phase resistance is 100000, this would return 0x0000000186A00001 (Status 1, 100000 is 0x186A0 in hexadecimal).

Command 9: Phase inductance measurement

This command is used to measure the phase inductance of the motor in uH.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically aborted. More information about this operation mode can be found in the Diagnostics opmode.

Command request

The values in 0x1023:1 for this command are as follows:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

9

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and with response

1

Phase inductance [MSB]

Phase inductance [MSB-1]

Phase inductance [MSB-2]

Phase inductance [LSB]

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The measured motor phase inductance is written in bytes 2, 3, 4 and 5.

  • Status 3: The command was finished unsuccessfully. Either a:ref:general OS error code<50_os_command_general_errors> or a command-specific OS error code will be sent.

OS error code

Error name

Error description

0

Current ampl. error

Unable to increase the current amplitude.

Example

To measure the motor phase inductance of our setup, we would need to:

  1. Switch to diagnostics mode, enter operation enable and disengage the brake if there is one. For details please refer to Diagnostics opmode.

  2. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 9. In the terminal the following command can be used:

    ethercat download 0x1023 1 0x09 --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    In case the motor phase inductance is 4000, this would return 0x0000000010940001 (Status 1, 4244 is 0x1094 in hexadecimal).

Command 10: Torque constant measurement

This command is used to measure the torque constant of the motor in mNm/A RMS.

This command can only be run when the operation mode is -2 (OPMODE_DIAGNOSTICS) and the CiA402 state is Operation enabled. If any of these conditions is not true during the execution of the command, it will be automatically aborted. More information about this operation mode can be found in Diagnostics opmode.

Command request

The values in 0x1023:1 for this command are as follows:

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Byte 0

0x0A

Command response

Description

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Command in progress (without percentage)

255

Command completed without errors and with response

1

Torque constant [MSB]

Torque constant [MSB-1]

Torque constant [MSB-2]

Torque constant [LSB]

Command completed with error and response

3

OS error code

  • Status 255: The command is in progress.

  • Status 1: The command was finished successfully. The measured motor phase inductance is written in bytes 2, 3, 4 and 5.

  • Status 3: This command doesn’t have any command-specific OS error code, so this status will only happen when a general OS error code occurs.

Example

For measuring the motor torque constant:

  1. Switch to diagnostics mode, enter operation enable and disengage the brake if there is one. For details please refer to Diagnostics opmode.

  2. Execute the OS command.

    Set Byte 0 of 0x1023:1 to 10 (0xA). In the terminal the following command can be used:

    ethercat download 0x1023 1 0x0A --type int64
    

    To fetch the response, enter the following command:

    ethercat upload 0x1023 3 --type int64
    

    In case the motor torque constant is 1203210, this would return 0x000000125C0A0001 (Status 1, 1203210 is 0x125C0A in hexadecimal).

Parameters

Selects, starts and reports the status of the command that should be used.

Orders the next command to be processed or aborts all commands.