Scope

This example covers how to load an ESI File to the SDK and how to enable the CiA 402 device profile.

CiA 402 Example

This example configures a 3 axes motor control application. If the device or the ESI file (EtherCAT Slave Information) does not support the CiA 402 device profile, the subsequent registration calls should be disabled. The following functions are implemented in ESL_cia402Demo.c.

EC_SLV_APP_motionControl

Motion control is done in this function. The control of modes CSP, CSV or CST is shown.

EC_SLV_APP_cia402Application

The function contains an implementation of the CiA 402 State Machine (although an external one can be registered). This state machine works alongside the CiA 402 application. The application reads the control object (0x6040) and writes the status object (0x6041). The application activates the axis and checks if there is any error pending. If an error is pending then it calls to transition actions to resolve the error and clears the error status if required.

EC_SLV_APP_cia402LocalError

If the CiA 402 State machine changes to an error state this function is called. It is used to notify the error, not to take any action.

Basic Setup

The example starts by initializing operating system (OSAL) and hardware abstraction layers (HWAL). The EtherCAT functionality itself is implemented within the EC_SLV_APP_loopTask that is started from the main application entry point, both are implemented in EtherCAT_Slave_ESI_Parser.c.

Hardware Setup

EC_SLV_APP_loopTask starts with the initialization of the GPIO driver and the configuration of the PHY and LED pins in the function EC_SLV_APP_initBoardFunctions in ecSlvESI.c.

Next PHY parameters, such as address, polarity and RX link are configured in EC_SLV_APP_registerStacklessBoardFunctions. The KUNBUS EtherCAT SDK supports Texas Instruments TLK105, TLK110 and Microchip KSZ8041NL PHYs by default. Alternative PHYs may be used. In this case the SDK user has to implement and register the functions to handle the new PHYs. Use the ESL_phyLibTlk110 sources as reference to implement your own PHY driver.

Program flow of the EtherCAT Slave ESI Parser Example Application
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Initialization of Stack, PRU, and Device Identification

Before entering the main stack loop, the example application itself is initialized in EC_SLV_APP_applicationInit. This function creates a new EtherCAT Slave device instance, registers a board status LED callback, sets vendor ID, product code and name, revision number, etc.

Program flow of the EtherCAT Slave ESI Parser Example Application
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After the basic initialization, EC_SLV_APP_applicationInit continues with the setup of the CiA 402 example drives and motion control example.

CiA 402 Basics

CiA402 State Machine

CiA402 State Machine or Finite State Automation (FSA) is independent to the EtherCAT State Machine (ESM) and defines internal and external behaviour for each state. The state of the drive determines which commands are accepted and whether high power is applied. States are changed when a control-word from the host-controller is received. They can also be changed due to internal events. The current state is indicated by the status-word. The control-word and different command values (e.g. velocity) are mapped into default RxPDOs (receive process data objects). The status-word and different actual values (e.g. position) are mapped into TxPDOs.

For a detailed description of the state machine transition please refer to the chapter 5.1 of the ETG6010 CiA402 implementation directive.

CiA402 State Machine
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Control Word

The control object 0x6040 is used to request state changes on the CiA402 state machine. The control commands are coded by bits.

Bit	Description
0	Switch on
1	Enable voltage
2	Quick Stop
3	Enable Operation
4-6	Operation mode specific
7	Fault reset

These defines are available to transition between different states.

Define	Value	Description
CONTROLWORD_COMMAND_SHUTDOWN	0x0006	Shutdown command
CONTROLWORD_COMMAND_SWITCHON	0x0007	Switch on command
CONTROLWORD_COMMAND_SWITCHON_ENABLEOPERATION	0x000F	Switch on and enable command
CONTROLWORD_COMMAND_DISABLEVOLTAGE	0x0000	Disable voltage command
CONTROLWORD_COMMAND_QUICKSTOP	0x0002	Quickstop command
CONTROLWORD_COMMAND_DISABLEOPERATION	0x0007	Disable operation command
CONTROLWORD_COMMAND_ENABLEOPERATION	0x000F	Enable operation command
CONTROLWORD_COMMAND_FAULTRESET	0x0080	Fault reset command

Status Word

The status object 0x6041 is used to get the state of the CiA402 state machine.

Bit	Description
0	Ready to switch on
1	Switched on
2	Operation enabled
3	Fault
4	Voltage enabled
5	Quick Stop
6	Switch on disabled

These defines are available to interpret the FSA states.

Define	Value	Description
STATUSWORD_STATE_NOTREADYTOSWITCHON	0x0000	Not ready to switch on
STATUSWORD_STATE_SWITCHEDONDISABLED	0x0040	Switched on but disabled
STATUSWORD_STATE_READYTOSWITCHON	0x0021	Ready to switch on
STATUSWORD_STATE_SWITCHEDON	0x0023	Switched on
STATUSWORD_STATE_OPERATIONENABLED	0x0027	Operation enabled
STATUSWORD_STATE_QUICKSTOPACTIVE	0x0007	Quickstop active
STATUSWORD_STATE_FAULTREACTIONACTIVE	0x000F	Fault reaction active
STATUSWORD_STATE_FAULT	0x0008	Fault state

Operation modes

These modes are recommended to be supported by the drives:

Operation mode	Code
Profile position mode	1
Velocity mode	2
Profile velocity mode	3
Torque profile mode	4
Homing mode	6
Interpolated position mode	7
Cyclic synchronous position mode	8
Cyclic synchronous velocity mode	9
Cyclic synchronous torque mode	10
Cyclic synchronous torque mode with commutation angle	11

The operation mode object 0x6060 is used to request an operation mode.

The operation mode display object 0x6061 is used to get the current operation mode.

Position control

The target position object 0x607A is used to request the target position.

The position actual value object 0x6064 gets the drive's current position.

Velocity control

The target velocity object 0x60FF is used to request the target velocity.

The velocity actual value object 0x606C gets the drive's current velocity.

Torque control

The target torque object 0x6071 is used to request the target torque.

The torque actual value object 0x6077 gets the drive's current torque.

Request object summary

These are the objects that must be written to the drive to command a specific operation.

Index	Description
0x6040	Control Word
0x6060	Operation mode
0x607A	Target position
0x60FF	Target velocity
0x6071	Target torque

Feedback object summary

These are the objects that must be read to get the current status of the drive.

Index	Description
0x6041	Status Word
0x6061	Operation mode display
0x6064	Position actual value
0x606C	Velocity actual value
0x6077	Torque actual value

Using CiA 402 Example on TwinCAT

The CiA402 demo simulates a three axes application. For each axis the objects described above are mapped as process data. Therefore, the first step is to scan the device and bring it to Operational state.

CiA402 runs in OP
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Open the Drive 1, the CiA402 mapped objects can be accessed there:

CiA402 example process data
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Go to the Modes of operation object and set the cyclic synchronous position mode (8):

Set value dialog
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Online view
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Go to the Modes of operation display object. It will show that the cyclic synchronous position mode has been set:

Online view
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Go to the Target position object and set a desired position for the axis:

Set value dialog
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Go to the Position actual value object. As we did not enable the operation, the axis did not move:

Online view
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Go to the Controlword object and set the switch on and enable operation commands (0x000F):

Set Value Dialog
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Online view
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Go to the Statusword object. It will show that drive has been switched on and the operation has been enabled:

Online view
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Finally, go to the Position actual value object again. As the operation has been enabled, the axis reached the target position (65536):

Online view
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The written values as well as the values provided by the drive simulation can be seen in the object dictionary.

Object Dictionary
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The rest of the axes and other operation modes can be configured following the same steps described above. Furthermore, there are more objects used for the drive application but this example covers only the basic configuration. Please refer to the ETG6010 document for a detailed description of the CiA402 directive.