Configure the EtherNet/IP Connector
Configure EtherNet/IP instances and items, discover controllers and tags, use symbolic and PCCC addresses, and troubleshoot communication.
The EtherNet/IP Connector reads and writes controller tags over EtherNet/IP. Use it with supported Allen-Bradley controllers and Omron NJ/NX controllers.
This guide explains manual configuration, device and item discovery, symbolic and PCCC addressing, arrays, data types, and troubleshooting.
Prerequisites
- Install the EtherNet/IP Connector.
- Connect SIA Connect and the controller to networks where they can reach each other.
- Allow EtherNet/IP traffic on TCP and UDP port
44818where required. - Enable external tag access in the controller project.
- Identify the controller family and the route to the CPU.
- For manual item creation, identify the exact tag names or PCCC addresses and their data types.
Only expose and write tags that are safe for the application. A write can affect controller logic and connected equipment.
Supported controller types
| Controller type | Default path behavior | Item discovery |
|---|---|---|
| Micro800 | No path is added automatically. | Supported |
| MicroLogix | Enter a path when required by the network route. | Not supported |
| CompactLogix | Uses 1,0 when Path is empty. |
Supported |
| SLC500 | Enter a path when required by the network route. | Not supported |
| PLC5 | Enter a path when required by the network route. | Not supported |
| ControlLogix | Uses 1,0 when Path is empty. |
Supported |
| FlexLogix | Enter a path when required by the network route. | Not supported |
| Omron NJ/NX | Enter the route required by the controller and network. | Not supported |
Device discovery can find devices that respond to the EtherNet/IP identity request. Item discovery has the narrower controller support shown above.
Discover EtherNet/IP devices
Device discovery broadcasts an EtherNet/IP identity request and creates an instance candidate for each device that responds.
- Open Workspace > Instances.
- Start instance discovery and select the EtherNet/IP Connector.
- Set the scan duration when required.
- Start the discovery.
- Review the product name, address, vendor, revision, serial number, detected controller type, and path for each candidate.
- Select and import the required candidates.
- Open each imported instance and confirm that Controller type and Path match the controller configuration.
The default discovery duration is 5000 ms. The Connector accepts durations from 500 to 60000 ms.
Discovery uses IPv4 broadcast traffic on UDP port 44818. Broadcasts normally remain within the local network. Devices across a router may need to be configured manually.
The Connector identifies the controller family from the product information returned by the device. If the product cannot be classified, it is treated as CompactLogix. Always verify the imported controller type and path before enabling process items.
Configure an instance manually
- Open Workspace > Instances.
- Create an instance and select the EtherNet/IP Connector.
- Enter a clear name for the instance.
- Enter the controller IP address or hostname in Address.
- Select the correct Controller type.
- Enter the CIP route in Path when required.
- Create the instance.
Instance parameters
| Parameter | Required | Default | Description |
|---|---|---|---|
| Address | Yes | None | IP address or resolvable hostname of the EtherNet/IP device or gateway. |
| Path | Depends on controller and route | Empty | Extended CIP route from the addressed device or gateway to the target CPU. CompactLogix and ControlLogix use 1,0 automatically when this field is empty. |
| Controller type | Yes | Micro800 | Selects the controller protocol and data representation used by the Connector. |
For an Omron NJ/NX connection, enter the route required by the controller. A route can use a format such as 18,192.168.1.20, where the address is replaced with the target controller address.
Discover controller items
Item discovery is available for Micro800, CompactLogix, and ControlLogix instances.
- Open the EtherNet/IP instance.
- Start item discovery.
- Wait while the Connector browses the controller tags.
- Review the candidates and discovery warnings.
- Select the required candidates.
- Import the selected items.
Discovery imports supported atomic tags, one-dimensional arrays, strings, and supported fields inside user-defined types. Discovered items are configured for read and write access.
Discovery skips:
- System tags
- Unsupported atomic or structured types
- Multidimensional arrays
- String arrays
- Recursive user-defined type structures
- User-defined types whose definitions are not returned by the controller
Importing an item with read and write access does not guarantee that the controller permits writing. Confirm the tag access setting in the controller project before using the item as a mapping receiver.
Configure an item manually
- Open the EtherNet/IP instance.
- Create an item.
- Enter a clear item name.
- Enter the controller tag or PCCC address in Address.
- Select the matching Data type.
- Configure the item's access and polling settings as required.
- Create the item.
Item parameters
| Parameter | Required | Default | Description |
|---|---|---|---|
| Address | Yes | None | Exact symbolic tag name, array range, bit address, or PCCC address in the controller. |
| Data type | Yes | Byte | Controls how the Connector reads, formats, and writes the tag value. It must match the controller tag. |
Supported data types
| Data type | Value representation |
|---|---|
| Bool |
0 or 1
|
| Small integer | Signed 8-bit integer from -128 to 127
|
| Unsigned small integer | Unsigned 8-bit integer from 0 to 255
|
| Byte | Unsigned value from 0 to 255
|
| Integer | Signed 16-bit integer from -32768 to 32767
|
| Unsigned integer | Unsigned 16-bit integer from 0 to 65535
|
| Word | Unsigned 16-bit value from 0 to 65535
|
| Double integer | Signed 32-bit integer from -2147483648 to 2147483647
|
| Unsigned double integer | Unsigned 32-bit integer from 0 to 4294967295
|
| Double word | Unsigned 32-bit value from 0 to 4294967295
|
| Real | 32-bit floating-point value |
| LReal | 64-bit floating-point value |
| String | Text value using the string representation of the selected controller type |
Micro800 strings support up to 80 characters. String arrays are not supported.
Address symbolic tags
Use the tag name and scope defined in the controller project.
| Purpose | Example |
|---|---|
| Global tag | Bottle_Counter |
| Program-scoped tag | Program:BottleManager.Bottle_Counter |
| Array element | Bottle_Counter[4] |
| Bit in a tag | Bottle_Counter.2 |
| Bit in an array element | Bottle_Counter[4].2 |
Micro800 tags must be global before they can be accessed externally.
Read and write arrays
Use an inclusive range inside square brackets. For example, Temperature[0-9] reads ten elements, starting at element 0 and ending at element 9.
Array reads return a compact JSON array. Write arrays using valid JSON, such as [10,20,30].
If a write contains more values than the configured range, the Connector ignores values beyond the range. If it contains fewer values, only the supplied elements are updated.
String arrays and multidimensional array discovery are not supported.
Address PCCC data files
MicroLogix, SLC500, and PLC5 controllers can use PCCC data-file addresses over EtherNet/IP. A bridge or gateway may be required when the target controller is reached through DH+ or another network.
| Purpose | Syntax or example |
|---|---|
| General format | <file type><file number>:<element> |
| Bit address |
B3:2/6 or B3:2.6
|
| Floating-point value | F8:0 |
| Integer value | N7:0 |
| Bit in an integer element | N7:0/4 |
| Input | I0:20/2 |
| Output | O0:10/2 |
| Long integer | L9:0 |
| String | ST9:0 |
Enter the gateway address in Address and the route to the target controller in Path when a bridge is used.
Verify communication
- Enable the EtherNet/IP instance and its items.
- Open the instance and confirm that it has no connection error.
- Confirm that item values update at the configured interval.
- Check that each value matches the corresponding controller tag.
- For a writable tag, perform a controlled write only when it is safe.
- Confirm the value in the controller and verify that the item reads back the expected result.
Troubleshoot the EtherNet/IP Connector
| Issue or message | Cause | Action |
|---|---|---|
| No devices are discovered | The devices are not on the local broadcast network, UDP port 44818 is blocked, or the scan duration is too short. |
Confirm the network interface, subnet, routing, and firewall rules. Increase the scan duration. Configure devices manually when they are separated by a router. |
| The discovered controller type or path is incorrect | The product information could not be classified accurately. | Edit the imported instance. Select the correct Controller type and enter the route required by the controller. |
Timeout connecting to PLC or Error: timeout
|
The controller or gateway did not respond before the connection or data timeout. | Confirm the address, controller power, network settings, route, and TCP port 44818. Test the address with the Ping tool. |
Error connecting to PLC or Error: create
|
The Connector could not create the controller tag connection. | Confirm the Controller type, Path, Address, controller access settings, and tag syntax. |
Error: not found |
The configured tag or PCCC address was not found. | Check spelling, capitalization, program scope, array index, PCCC file address, and whether the tag is available for external access. |
Error: bad param |
An instance parameter, tag address, array range, or selected data type is invalid. | Check Address, Path, Controller type, item Address, and Data type. Make sure an array range ends after it starts. |
Write array error: Invalid format. Write message: ... |
The array write value is not valid JSON. | Use a JSON array such as [10,20,30]. Check commas, brackets, quotation marks, and element values. |
Item discovery is supported for Micro800, CompactLogix and ControlLogix devices only. |
Item discovery was started for another controller type. | Create items manually using the correct symbolic or PCCC addresses. |
Discovery helper timed out while browsing PLC tags |
The controller did not finish returning its tag information within 60 seconds. | Confirm the controller connection and Path. Reduce controller or network load, then run discovery again. |
Discovery helper not found: ... or Required discovery runtime is missing
|
The Connector installation is incomplete. | Reinstall or update the EtherNet/IP Connector, then retry discovery. |
| An expected item is missing from discovery | The tag is a system tag, unsupported type, multidimensional array, string array, recursive structure, or an unavailable UDT field. | Review the discovery warnings. Create a supported atomic tag or one-dimensional array manually when appropriate. |
| A String value is empty or incorrect | The selected Controller type does not match the controller's string format, or the tag is a string array. | Select the correct Controller type. Confirm the tag is a supported single String and test it directly in the controller project. |
| A write fails or is rejected | The controller tag is read-only, external write access is disabled, the data type does not match, or the value is outside the accepted range. | Check the controller tag permissions, selected Data type, value range, and controller diagnostics. |