Omron SYSMAC CJ1W-EIP21 - Manual (Page 409)

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CIP Message Communications Appendix D
Route Path
Route Path
In the CIP, unlike the internet protocol, the transmission frame contains a complete relay route from the trans-
mission node to the reception node. The described route is called the “route path.” The route path is described
as “EPATH type.”
The basic concept of the route path is as follows:
First of all, specify a network port of the transmission node with the destination network, and specify a node
address (called the Link Address) on that network. For the relay node, similarly, specify a network port with the
destination network and node address on that network. Then, repeat the same procedure to the final destina-
tion.
Description by EPATH Type
In CIP, the EPATH type is used to describe the route path and request path.
With this method, the route path and request path are divided into segments and a value is assigned to each
segment, so the route path description shows the path to the final destination when the data segments are
joined together.
The segment includes the segment type information and the segment data.
Details of Segment Type
The interpretation method of a segment is included in the first 1 byte, which consists of two parts; a 3-bit “Seg-
ment Type” and a 5-bit “Segment Format.”
#1 #3 #2 #1
Object A Object B
Route Path = Port A: #3, Port C: #1
X Y Z
When sending data from X to Z.
Send data from the network port of X (Port-A) to #3 on that circuit, and the data
reaches Y. Then, send it from the network port of Y (Port-C) to #1 on that circuit.
Through this procedure, the destination node Z can be designated.
Port-A Port-B Port-C Port-D
Segment 1 Segment 2 Segment 3 Segment 4 · · · ·
Segment Type Segment Format
7 6 5 4 3 2 1 0