Object 345Ah: Brake Control

These objects implement the possibility to control the brake directly, overriding the drive logic. When the brake state is controlled by the fieldbus, the drive state (enabled, disabled, faulted) will have no effect on the brake - the fieldbus will be in control.


  • Applying or releasing the brake at the wrong time can be a safety hazard and can destroy your mechanic as well as drive or motor. Unexpected behaviour might be possible. It is the responsibility of the customer using this mode to use this function appropriately.

 

When fieldbus control is disabled, the drive will control the brake as defined by existing AKD brake related parameters. As soon as fieldbus control is enabled, the Brake Command received over the field bus will take effect. So, if the Brake Command is set to APPLY and the current state is RELEASE, the brake will begin to apply .

The default value of the fieldbus control will be disabled, so that the drive is always in control until the fieldbus is operational. It is recommended that this bit remain 0 except for special operating conditions where the fieldbus will control the brake. When fieldbus communication is lost, the drive will regain control of the brake if the fieldbus had previously taken control.

Enable FieldbusClosedA Fieldbus is an industrial network system for real-time distributed control (e.g. CAN or Profibus). It is a way of connecting instruments in a plant design Control Serious Failur econdition present Brake Command Fieldbus Control Status Controlled by... Final Brake State
0 x x 0 Drive Drive
1* no 0 1 Fieldbus Applied
1* no 1 1 Fieldbus Released
x yes any 0 Drive Drive

1* indicates that a rising edgeClosedA rising edge is the transition of a digital signal from low to high. It is also called positive edge was seen since the last time the drive applied the brake

 

Index

345Ah

Name

Brake Control

Object code

ARRAY

Data type

UNSIGNED16

Category

optional

Defined sub-indices

Subindex

0

Name

highest sub-index supported

Data type

UNSIGNED8

Category

mandatory

Access

R/O

PDO Mapping

not possible

Value Range

2

Default Value

2

 

Subindex

1

Name

Brake Control Command

Category

optional

Access

R/W

PDO Mapping

possible

Value Range

UNSIGNED16

Default Value

0

With subindex 1 the brake is controlled. Bit definition:

Bit

Name

Description

0

Enable fieldbus
control

0 - brake is not controlled via this object
1 - enable fieldbus control via this object. This function works edge triggered, i.e. this bit has to have a 0 -> 1 transition to activate the brake control functionality. After a fault the functionality is reset and has to be activated again. The activation can be controlled by subindex 2 bit 0.

1

Brake Command

This command bit is only active, if the functionality was activated via bit 0. The function is as follows:
0 - apply the brake
1 - release the brake

 

Subindex

2

Name

Brake Status Response

Category

optional

Access

R/O

PDO Mapping

possible

Value Range

UNSIGNED16

Default Value

0

With subindex 2 the brake status can be checked. Bit definition:

Bit

Name

Description

0

Fieldbus control Status

0 - brake control via 0x345A is disabled or not possible due to drive failure.
1 - enable fieldbus control via this object. This function works edge triggered, i.e. this bit has to have a 0 -> 1 transition to activate the brake control functionality. After a fault the functionality is reset and has to be activated again. The activation can be controlled by subindex 2 bit 0.

1

Brake Status

0 - apply the brake
1 - release the brake
Note: When the brake is applied or released, there is a time delay MOTOR.TBRAKEAPP or MOTOR.TBRAKEREL, after the receipt of the command before this status bit changes. The status is always reported: it is not affected by fieldbus control.

2

STO Status

0 - STO is not active (drive may be enabled)
1 - STO is active (drive can not be enabled)

3

HW Enable Status

0 - HW enable is disabled, drive function can not be enabled
1 - HW enable is enabled, drive function can be enabled