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 FieldbusA 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 edgeA 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