384 cip message communications appendix d, Port segment – Omron SYSMAC CJ1W-EIP21 User Manual
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384
CIP Message Communications
Appendix D
According to CIP Specifications, the Segment Type specifications are decided as follows:
The specifications of Segment Format are different for each Segment Type.
The following sections describe Port Segment, Logical Segment, and Data Segment which are needed to use
the CIP message communications instructions.
Port Segment
The Port Segment is used to specify the path described above.
Set the ID of the port in Port Identifier.
The Port Identifier is 4 bits, so it can have a value between 0 and 15. A port identifier of “0” is reserved and not
available. A port identifier of “1” indicates the backplane port.
A port identifier of “15” has a special meaning, which indicates that the size of Port Identifier is larger than
1 byte, and the 4-bit port identifier (15) is followed by 2-byte Port Identifier. The port identifier does not exceed
1 byte when using the EtherNet/IP Unit or built-in EtherNet/IP port, so this special case is not explained here.
Set the Extended Link Address Size to “1” when that port’s Link Address is larger than 1 byte.
The following diagram shows the Port Segment value when the Extended Link Address Size is set to “0.”
Segment Type
Description
7
6
5
0
0
0
Port Segment
0
0
1
Logical Segment
0
1
0
Network Segment
0
1
1
Symbolic Segment
1
0
0
Data Segment
1
0
1
Data Type
1
1
0
Data Type
1
1
1
Reserved
Segment Type
Port Identifier
7 6 5
4 3
2
1 0
0 0 0
Extended Link
Address Size
Segment Type
Port Identifier
7
6
5
4
3
2
1
0
0
0
0
Extended Link
Address Size
0
7
6
5
4
3
2
1
0
Link Address