Message Segmentation
191
Doc.Id. HMSI-27-212
Anybus CompactCom 40 EtherNet/IP
Doc.Rev. 1.5
C.3 Response Segmentation
When a response is segmented, the command initiator requests the next segment by sending the same
command multiple times. For each response, the data field is exchanged with the next data segment.
Response segmentation is used for responses to the following commands:
• Receive (object specific, see “Command Details: Receive” on page 118)
• Receive From (object specific, see “Command Details: Receive_From” on page 119)
• Get_Configuration_Data (see “Command Details: Get_Configuration_Data” on page 170)
Segmentation Control bits (Command)
Segmentation Control bits (Response)
When receiving a segmented response, the following rules apply:
• In the first segment, FS is set
• In all subsequent segment, both FS and LS are cleared
• In the last segment, LS is set
• For single segment responses (i.e. size less or equal to 255 bytes), both FS and LS are set.
• The command initiator may at any time abort the operation by issuing a message with AB set.
Bit
Contents
Meaning
0
(reserved)
(set to zero)
1
2
AB
Set if the segmentation shall be aborted
3...7
(reserved)
(set to zero)
Bit
Contents
Meaning
0
FS
Set if the current segment is the first segment
1
LS
Set if the current segment is the last segment
2...7
(reserved)
(set to zero)