Análisis práctico

Fig. 5.1 Status diagram of the motor controller

The status diagram can be roughly divided into three areas: "Power Disabled" means that the final stage is switched off and "Power Enabled" that the final stage is switched on.

The statuses needed for handling errors are summarised in the "Fault" area.

The most important statuses of the motor controller are shown highlighted in the diagram.

After it is switched on, the motor controller initialises itself and then reaches the status SWITCH_ON_DISABLED. In this status, the CAN communication is completely function capable and the motor controller can be parametrised (e.g. the "speed adjustment"

operating mode is set). The final stage is switched off and the shaft is thus freely

rotatable. Through the status transitions 2, 3, 4 – which correspond in principle to the CAN controller enable – one reaches the status OPERATION_ENABLE. In this status, the output stage is switched on and the motor regulated in accordance with the set operating mode.

Therefore, you should always make sure beforehand that the drive is correctly parametrised and that a corresponding setpoint value equals zero.

The status transition 9 corresponds to removal of the output stage release, that is, a motor that is still running would fizzle out unregulated.

If an error occurs (regardless from which status), the system ultimately branches into the FAULT status. Depending on the severity of the error, certain actions, such as emergency braking, can still be performed (FAULT_REACTION_ACTIVE).

In order to perform the named status transitions, certain bit combinations must be set in the controlword (see below). The lower 4 bits of the controlwords are jointly evaluated in order to trigger a status transition. In the following, first only the most important status transitions 2, 3, 4, 9 and 15 are explained. A table of all possible statuses and status transitions are found at the end of this chapter.

The following table contains the desired status transition in the 1st column and in the 2nd column the requirements necessary for it (usually a command through the host, here depicted with frame). How this command is generated, that is, which bits must be set in the controlword, is evident in the 3rd column (x = not relevant).

Bit combination (controlword) No. Is performed when

Bit 3 2 1 0

Action

2 Output stage and controller enable

prev. + command Shutdown Shutdown = x 1 1 0 None

3 Command Switch On Switch On = x 1 1 1 Switching on the final stage

4 Command Enable Operation Enable Operation = 1 1 1 1 Control in accordance with set operating mode 9 Command Disable Voltage Disable Voltage = x x 0 x Final stage is blocked.

Motor rotates freely.

15 Error eliminated+

command Fault Reset Fault Reset = Bit 7 = Acknowledge error

Table 5.1: Most important status transitions of the motor controller

EXAMPLE

After the motor controller has been parametrised, the motor controller should be "enabled", that is, the output stage switched on:

1.) The motor controller is in the status SWITCH_ON_DISABLED 2.) The motor controller should be in the status OPERATION_ENABLE

3.) The transitions 2, 3 and 4 are to be carried out according to the status diagram (Fig. 5.1).

4.) From Table 5.1 follows:

Transition 2: controlword = 0006h New status: READY_TO_SWITCH_ON *¹⁾ Transition 3: controlword = 0007h New status: SWITCHED_ON *¹⁾

Transition 4: controlword = 000Fh New status: OPERATION_ENABLE *¹⁾ Notes:

1.) The example assumes that no other bits are set in the controlword (for the transitions, only bits 0 … 3 are important).

2.) Transitions 3 and 4 can be combined by setting the controlword immediately to 000Fh. For status transition 2, the set bit 3 is not relevant.

*¹⁾ The host must wait until the status in the statusword can be read back. This is explained in detail below.

Status diagram: statuses

The following table lists all statuses and their meaning:

Name Significance

NOT_READY_TO_SWITCH_ON The motor controller performs a self-test. The CAN communication does not work yet.

SWITCH_ON_DISABLED The motor controller has completed its self-test. CAN communication is possible.

READY_TO_SWITCH_ON The motor controller waits until the digital inputs "output stage" and

"controller enable" are at 24 V.

(Controller enable logic "Digital input and CAN").

SWITCHED_ON ^*1) The final stage is switched on.

OPERATION_ENABLE ^*1) Voltage to the motor is on, and the motor is regulated according to the operating mode.

QUICKSTOP_ACTIVE ^*1) The quick stop function is carried out (see: quick_stop_option_ code).

Voltage to the motor is on, and the motor is regulated according to the quick stop function.

FAULT_REACTION_ACTIVE ^*1) An error has occurred. In case of critical errors, the system immediately switches into the Fault status. Otherwise, the action specified in the fault_reaction_option_code is carried out. Voltage to the motor is on, and the motor is regulated according to the fault reaction function.

FAULT An error has occurred. No voltage is applied to the motor.

*¹⁾ The final stage is switched on.

Status diagram: Status transitions

The following table lists all statuses and their meaning:

Bit combination (controlword) No. Is performed when

Bit 3 2 1 0

Action

0 Switched on or reset occurs Internal transition Perform self-test 1 Self-test successful Internal transition Activation of CAN

communication 2 Output stage and controller enable

prev. + command Shutdown Shutdown = x 1 1 0 -

3 Command Switch On Switch On = x 1 1 1 Switching on the final stage

4 Command Enable Operation Enable Operation = 1 1 1 1 Control in accordance with set operating mode Final stage is blocked.

Bit combination (controlword) No. Is performed when

Bit 3 2 1 0

Action

6 Command Shutdown Shutdown = x 1 1 0 Final stage is blocked.

Motor rotates freely 7 Command Quick Stop Quick Stop = x 0 1 x -

8 Command Shutdown Shutdown = x 1 1 0 Final stage is blocked.

Motor rotates freely 9 Command Disable Voltage Disable Voltage = x x 0 x Final stage is blocked.

Motor rotates freely.

10 Command Disable Voltage Disable Voltage = x x 0 x Final stage is blocked.

Motor rotates freely

11 Command Quick Stop Quick Stop = x 0 1 x

Braking is introduced in accordance with quick_stop_option_code. 12 Braking ended without command

Disable Voltage Disable Voltage = x x 0 x Final stage is blocked.

Motor rotates freely

13 Error occurred Internal transition

In case of uncritical errors, reaction according to fault_reaction_option_code. For critical errors, transition 14 occurs 14 Error resolution is ended Internal transition Final stage is blocked.

Motor rotates freely 15 Error eliminated+

command Fault Reset Fault Reset = Bit 7 = Acknowledge error (with rising flank)

Caution

Output stage blocked …

… means that the power semiconductors (transistors) can no longer be actuated. If this status is taken with a turning motor,

it fizzles out unbraked. If a mechanical motor brake is present, it is automatically actuated.

The signal does not guarantee that the motor is really voltage-free.

Caution

Output stage and controller enable enabled …

… means that the motor is actuated and regulated according to the chosen operating mode. If a mechanical motor brake is present, it is automatically triggered. In case of a defect or incorrect parametrisation (motor current, number of poles, resolver offset angle, etc.), this can result in uncontrolled behaviour of the drive.