Data Object; Variable Data Object - HMS Anybus Communicator User Manual

7.5 Data Object

Data Objects are used to represent raw data as follows:
• Produce/Query Transactions
The specified data block is forwarded from the higher level network to the sub-network.
• Consume/Response Transactions
The specified data block is forwarded from the sub-network to the higher level network.
To specify the properties of the object, select it in the Navigation Section and enter the desired settings
in the Parameter section as follows:
Parameter
Byte Swapping
Data Length
Data Location

7.6 Variable Data Object

Note: Only one Variable Data Object is permitted for each transaction.
This object is similar to the Data Object, except that it has no predefined length. Instead, an End or
Length-character specifies the size of the data block as follows:
Data of arbitrary length
• Produce/Query Transactions
The specified data block will be forwarded from the higher level network to the sub-network.
The control system must supply an End or Length character in order for the gateway to know
the size of the data block.
The End- or Length-character itself may either be forwarded to the sub-network or discarded.
• Consume/Response Transactions
The specified data block is forwarded from the sub-network to the higher level network. The
End- or Length-character will be generated by the gateway automatically (if applicable).
The End- or Length-character itself may either be forwarded to the higher level network or dis-
carded.
Anybus Communicator PROFINET User Manual
Description
• No Swapping
No swapping is performed on the data
• Swap 2 bytes
A, B, C, D becomes B, A, D, C
• Swap 4 bytes
A, B, C, D becomes D, C, B, A
The length of the data block, in bytes. In case of a Response or Consume transaction, incom-
ing messages where the data size differs from the value specified here will be discarded. Max-
imum data length allowed for one frame is 300 bytes.
The location of the data block in the internal memory buffer.
(Variable Data Object)
Data 0x00
End Character
(Variable Data Object)
0x04 Data
Length Character 4 bytes of data
Doc: HMSI-27-309, Rev. 3.11
Frame Objects 38