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CS-series EtherNet/IP Unit


Introducing the New EtherNet/IP Unit. More Than 180,000 Words of Tag Data Link Capacity!

EtherNet/IP Unit Specifications

Item Specifications
Model number CS1W-EIP21
Type 100Base-TX (See note.)
Applicable PLCs CS-series PLCs
Unit classification CS-series CPU Bus Unit
Mounting location CPU Rack or Expansion Rack
Number of Units that can be mounted 8 max. (including Expansion Racks)
CPU Unit
words used
Allocated CIO Area
words (CPU Bus Unit
25 words/Unit (one unit number's words)
These words contain control bits and flags, the target node PLC's operating and error
information, Unit status, communications status, registered/normal target node information,
and FINS/TCP connection status.
Allocated DM Area
words (CPU Bus Unit
100 words/Unit (one unit number's words)
These words contain the IP address display/setting area
User-set area Any usable data area words
Target node PLC's operating and error information, and registered/normal target node
CPU Bus Unit System
Not used.
Non-volatile memory within
EtherNet/IP Unit (See note.)
The following settings are stored in the EtherNet/IP Unit's non-volatile memory.
Note: Unlike the regular Ethernet Units, the CPU Bus Unit Setup Area in the CPU Unit is not
used for these settings.
1. Unit setup (communications settings for the EtherNet/IP Unit, such as the IP address, DNS
server settings, host name, baud rate, FINS/UDP settings, and FINS/TCP settings)
2. Tag data link settings (device parameters)
Media access method CSMA/CD
Modulation method Baseband
Transmission paths Star form
Baud rate 100 Mbit/s (100Base-TX)
Transmission media Shielded twisted-pair (STP) cable
Categories: 100 Ω at 5, 5e
Transmission distance 100 m (distance between hub and node)
Number of cascade
There is no limitation when a switching hub is used.
Current consumption (Unit) 410 mA max. at 5 V DC
Weight 171 g max.
Dimensions 35 × 130 × 101 mm (W × H × D)
Other general specifications Other specifications conform to the general specifications of the CS-series

Note: If tag data links are being used, use 100Base-TX. Otherwise, 10Base-T can be used, but this is not recommended.

Communications Specifications

Item Specifications
Tag data
Number of connections 256
Packet interval
(refresh cycle)
0.5 to 10,000 ms (in 0.5-ms units)
Can be set independently for each connection.
(Data is refreshed over the network at the preset interval and
does not depend on the number of nodes.)
Maximum allowed
bandwidth per Unit
6,000 to 12,000 pps *1 *2
Number of tag sets 256
Tag types CIO Area, DM Area, EM Area, Holding Area, and Work Area
Number of tags per
connection (= 1 tag set)
8 (7 tags when the tag set contains the PLC status)
Maximum link data size
per node
184,832 words
Maximum data size per
252 words or 722 words *3
Note: Data synchronicity is maintained within each connection.
Number of registrable
tag sets
(1 connection = 1 tag set)
Maximum size of 1 tag
722 words
(The PLC status uses 1 word when the tag set contains the PLC
Maximum number of
tags that can be
refreshed per CPU Unit
cycle *4
Output/Transmission (CPU to EtherNet/IP): 19
Input/Reception (EtherNet/IP to CPU): 20 *5
Data that can be
refreshed per CPU Unit
cycle *4
Output/Transmission (CPU to EtherNet/IP): 7,405 words
Input/Reception (EtherNet/IP to CPU): 7,405 words
Changing tag data link
parameters during
Supported *6
Multicast packet filter
function *7
Class 3 (connected) Number of connections: 128
UCMM (unconnected) Number of clients that can communicate at one time: 32 max.
Number of servers that can communicate at one time: 32 max.
CIP routing CS1W-EIP21, CJ1W-EIP21, CJ2H-CPU6[]-EIP, CJ2M-CPU3[]
FINS service FINS/UDP Supported
FINS/TCP 16 connections max.
EtherNet/IP conformance test Conforms to A5
Ethernet interface 10BASE-T or 100BASE-TX
Auto Negotiation or fixed settings

*1. In this case, pps means "packets per second" and indicates the number of packets that can be processed in one
*2. To use 505 to 1,444 bytes as the data size, the system must support the Large Forward Open standard (an optional
       CIP specification). The CS/CJ-series Units support this standard, but before connecting to nodes of other companies,
       confirm that those devices also support it.
*3. If the maximum data size is exceeded, the data refreshing with the CPU Unit will extend over two or more cycles.
*4. If status layout is selected in the user settings, the maximum number of tags that can be received is 19 tags.
*5. If parameters are changed in the EtherNet/IP Unit, however, the EtherNet/IP Unit will be restarted. When other nodes
       are communicating with the affected node, the communications will temporarily time out and automatically recover
*6. Because the EtherNet/IP Unit is equipped with an IGMP client, unnecessary multicast packets can be filtered by using
       a switching hub that supports IGMP snooping.
*7. The EtherNet/IP Unit uses the TCP/UDP port numbers shown in the following table.

Service Protocol Port number Remarks
Tag data links UDP 2222 Fixed value
Class 3, UCMM TCP/UDP 44818
FINS/UDP service UDP 9600 Port numbers in the Unit Setup can be changed with
the CX-Programmer.
FINS/TCP service TCP 9600
FTP TCP 20, 21
SNMP trap UDP 162

Network Configurator Requirements

The Network Configurator Ver. 3.0 or higher is a software package designed for building, setting, and controlling a multi-vendor EtherNet/IP Network using OMRON's EtherNet/IP. It is included in CX-One version 3.0. The Network Configurator provides the following functions for building, setting, and controlling EtherNet/IP.

Item Specification
Operating environment CXONE-AL[][]D-V[]
Serial interface CPU Unit's Peripheral or RS-232C port CPU Unit's USB or RS-232C port
Ethernet interface EtherNet/IP Unit's Ethernet port CPU Unit's Ethernet port
EtherNet/IP Unit's Ethernet port
Location on Network A single node address is used (only when directly connected to EtherNet/IP).
Number of Units that can be
connected to Network
A single Network Configurator per Network
(More than one Configurator cannot be used in the same system.)
Network control
The Network configuration can be created and edited regardless of whether the
Network Configurator is online or offline.
The Network configuration can be read from a file or the network.
The EDS files used by the Network Configurator can be installed and deleted.
Supported file formats Configurator network configuration files (*.ncf)
Configuration files (*.ncf) created using the Network Configurator for EtherNet/IP
(version 2) can be imported by selecting External Data - Import from the File Menu.