Omron NX Series User Manual

12-1-2
Calculating the Number of Connections
The maximum number of connections per EtherNet/IP port on a CPU Unit is as follows.
•
256
The maximum number of connections for a Unit should not be exceeded by the total number of origi-
nator connections, which the Unit opens, and target connections, which other nodes open to the Unit.
Example)
Node 1 has two target connections with Node 2, and opens one originator connection to Node 3. So,
Node 1 has three connections in total.
Node 2 opens two originator connections to Node 1, and one originator connection to Node 3. So,
Node 2 has three connections in total.
Node 3 has one target connection with Node 1, and one target connection with Node 2. So, Node 3
has two connections in total.
In either case, the connections can be successfully opened since the total number of connections is
below the maximum number for an EtherNet/IP port, as shown above.
O
T
T
O
T
O
T
O
T: T
arget
O: Originator
Node 3Node 2
Node 1
If multicast is specified for data transmission and the node sends out just one multicast packet to other
nodes, it requires respective connections for them.
Example)
Node 3 sends out one multicast packet to Node 1 and Node 2. Node 3 has one target connection with
Node 1, and one target connection with Node 2, requiring two connections in total.
You need to keep in mind that the number of required connections is the same, whether multicast or
unitcast is specified for the communications.
T
O
T
O
T: T
arget
O: Originator
Multicast
Node 3
Multicast
Node 2
Node 1
12 Communications Performance and Communications Load
12-5
NX-series EtherNet/IP Unit User's Manual (W627)
12-1 Communications System
12
12-1-2 Calculating the Number of Connections

Omron NX Series Specifications

General

Brand	Omron
Model	NX Series
Category	Controller
Language	English