10. Appendix D: DeviceNet Objects

Attributes of instances 16#01 to 16#04 of class 16#05

Service code

Name of the service

Need

Description

16#0E

Get_Attribute_Single

Required

This service allows to read the value of one of the attributes from

 

 

 

one of the instances of the “Connection Object.”

16#10

Set_Attribute_Single

Optional

This service allows to write the value of one of the attributes from

 

 

 

one of the instances of the “Connection Object.”

10.9. Acknowledge Handler Object (class 16#2B)

The “Acknowledge Handler” object has only one instance (Instance ID = 16#01). This object is used by connections whose producer needs to know whether its data has been received by its recipient(s) (consumers). This object is described in chapter 6-31. of volume II of the DeviceNet specifications.

Attributes of class 16#2B

ID

Access

Name

Need

Type

Value

Description

16#01

Get

Revision

Optional

UINT

1

Revision index of the “Acknowledge Handler Object”

 

 

 

 

 

 

class.

16#02

Get

Max

Optional

UINT

1

Maximum number of any instance created within the

 

 

instance

 

 

 

“Acknowledge Handler Object” class.

Services in class 16#2B

Service code

Name of the service

Need

Description

16#0E

Get_Attribute_Single

Required

This service allows to read the value of one of the attributes of the

 

 

 

class.

Attributes of instance 16#01 of class 16#2B

ID

Access

Name

Need

Type

Value

16#01

Get / Set

Acknowledge timer

Required

UINT

20 (unit: 1ms)

The value of this attribute determines the waiting time for acknowledgement of the message from a connection. Once this time has elapsed, the gateway proceeds to re-transmit the message which has just failed to be acknowledged. The value of this attribute ranges from 1 to 65,535, and its default value is 20.

16#02

Get / Set

Retry limit

Required

USINT

1

This attribute determines the maximum number of times that the acknowledge timeout can be successively triggered for the same message, and therefore the number of re-transmissions allowed for each message. The value of this attribute ranges from 0 to 255, and its default value is 1.

16#03

Get / Set

COS producing connection instance

Required

UINT

4

The value of this attribute is set to the instance number (Instance ID) of the “Connection Object” class corresponding to the “Change-of-State” connection associated with the “Acknowledge Handler” object. This association allows the latter to transmit the acknowledgements it receives to the corresponding connection if they are addressed to it.

16#04

Get

Ack list size

Optional

BYTE

1

This attribute represents the maximum number of members which can be placed in the ack list. If the value of this attribute is null, the size of the list is dynamic, which is not the case with the LUFP9 gateway.

16#05

Get

Ack list

Optional

BYTE , USINT […]

0 , (empty list)

This attribute corresponds to the list of active instances of the “Connection Object” class for which the receipt of an acknowledgement is required. It is made up of two elements: The number of members (BYTE) and the list of the associated instance numbers from the “Connection Object” class (USINT […]). The size of the list is set to the value of the first element. By default, the list is empty (no term of the USINT type […]) and only the BYTE element is created.

E.g. “1, 4“ for a list comprising a single instance of the “Connection Object” class. This instance (16#04) corresponds to the “Change-of-State / Cyclic (Acknowledged) Connection”).

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Schneider Electric LUFP9 Acknowledge Handler Object class 16#2B, Attributes of instances 16#01 to 16#04 of class 16#05