The Omron FINS Connector connects SIA Connect to Omron PLCs and other controllers that support FINS communication over Ethernet. It supports FINS/TCP and FINS/UDP, instance discovery, memory-area reads and writes, scalar values, arrays, and strings.

This guide explains how to discover or create an Omron FINS instance, configure its network parameters, create items manually, select data types, verify communication, and resolve common errors.

Before you begin

Prepare the following information:

• The PLC hostname or IPv4 address.
• Whether the PLC uses FINS/TCP or FINS/UDP.
• The FINS port. The default is 9600.
• The source and destination network, node, and unit addresses required by the PLC configuration.
• The PLC memory areas, addresses, and data types you need to access.
• Whether strings require byte swapping.

Make sure that FINS communication is enabled on the correct PLC Ethernet interface and that SIA Connect can reach it through the network.

Discover Omron FINS instances

The Connector can discover FINS devices using UDP broadcast and a FINS/TCP node-address handshake. It can also probe IPv4 hosts on the selected interface for FINS/TCP.

1. In the Edge Portal, go to Configuration > Connectors.
2. Find the installed Omron FINS Connector.
3. Start instance discovery.
4. Configure the discovery parameters.
5. Start the scan.
6. Select the supported FINS devices you want to import.
7. Import the selected instances.

Discovery parameters

The TCP scan is limited to 256 hosts and 64 configured TCP ports. Use a specific network interface and narrow port range to reduce scan time.

A discovered instance is preconfigured with the detected address, protocol, port, and FINS node information. Review these values against the PLC configuration before using the instance.

Create an instance manually

1. In the Edge Portal, go to Instances.
2. Select Add instance.
3. Select the Omron FINS Connector.
4. Enter a descriptive instance name.
5. Enter the PLC hostname or IPv4 address in Address.
6. Configure the instance parameters.
7. Select Create.

Instance parameters

Values below 20 in the Timeout field are interpreted as seconds for compatibility with older Connector configurations. Enter a timeout in milliseconds when creating a new instance.

Create items

The Connector does not support item discovery because FINS does not provide tag browsing. Create each item from the PLC memory map.

1. Open the Omron FINS instance.
2. Open the Items tab.
3. Select Add item.
4. Enter a name and UID.
5. Enter the PLC memory location in Address.
6. Select the matching Data type.
7. Configure whether the item can be read, written, or both.
8. Configure the required read interval or event behavior.
9. Select Create.

Address syntax

Combine the Omron memory-area prefix with the memory location. Address ranges are inclusive.

The available memory areas and valid ranges depend on the PLC model and operating mode. Confirm every address in the Omron documentation for the connected controller.

Use a range for strings because each PLC word stores up to two characters. For example, D200-209 provides ten words, or up to 20 characters. Reading stops at the first null character.

Select a data type

Read arrays and strings

A range address returns multiple numeric values as a compact JSON array. For example, reading three Int values could return:

["10","20","30"]

Multiword data types use the required number of PLC words. For example, a range covering four words returns two 32-bit values or one 64-bit value.

A String item returns text instead of a JSON array. Change String byteswap on the instance if adjacent characters are reversed.

Write scalar values, arrays, and strings

For a single address, map one value to the item. For a range address, map a valid JSON array containing the values to write.

For example:

[10,20,30]

The Connector does not write more values than fit in the configured address range. A non-array value sent to a numeric range is rejected as an invalid array format.

For a String item, send the text value directly. If the string is longer than the selected address range, only the characters that fit are written.

When several writes to the same item are queued, the Connector uses the newest queued value.

Automatic identity items

After a successful connection, the Connector creates read-only identity items when the information is available:

• Vendor
• Model
• Firmware

Some PLCs do not support the CPU information command used for Model and Firmware. Communication can still continue, but only Vendor may be available.

Verify the configuration

1. Confirm that the instance and required items are enabled.
2. Check that the instance has no active connection error.
3. Confirm that the Vendor item reports Omron.
4. Open a known read item and compare its value with the PLC programming software.
5. Test a write only after confirming that the target is safe and writable.
6. Confirm the written value in the PLC and then read it back through SIA Connect.

Troubleshoot the Omron FINS Connector

The instance reports Timeout to PLC

• Confirm that the PLC is powered and reachable.
• Check the Address, Protocol, Port, and Timeout fields.
• Confirm that FINS is enabled on the selected PLC Ethernet interface.
• Check routing, subnet settings, and firewall rules.
• Confirm that the source and destination FINS addresses match the network configuration.

The instance reports Failed to connect to PLC

Confirm that the selected protocol is correct and that the PLC listens on the configured port. A TCP connection cannot be established against a UDP-only FINS configuration.

The client and server use the same FINS node

Assign different source and destination node values. For FINS/UDP, the source node normally corresponds to the final octet of the SIA Connect IPv4 address when the FINS network uses IP address conversion.

The item reports an invalid read or write address

Confirm the memory-area prefix, word number, bit offset, and range. Check that the area is available on the PLC model and that the selected Data type fits within the configured range.

The item reports Could not determine start address of byte

The range syntax could not be parsed. Use an inclusive range such as D200-209 and make sure the starting address includes a supported memory-area prefix.

The item reports Unknown type

Select a supported value in Data type. If the item was imported from an older configuration, edit and save it using one of the current data types.

An array write is rejected

Send a valid JSON array to numeric range items. Check the brackets, commas, quotation marks, and value types. The number of values must not exceed the capacity of the address range.

A string is truncated or has reversed characters

Increase the number of words in the address range if more characters are required. Change String byteswap between No swap and Swap when characters appear in pairs in the wrong order.

Real or Double values are incorrect

Confirm that the PLC stores the value as a 32-bit Real or 64-bit Double and that the start address and range cover two or four consecutive words respectively.

A discovered Omron device cannot be imported

The device answered the network scan but did not provide usable FINS CPU or data services on that interface. Check whether the device uses EtherNet/IP, whether FINS is enabled, or whether another Ethernet port provides FINS communication.

Discovery does not find the PLC

• Select the network interface connected to the PLC network.
• Confirm that the interface has a valid IPv4 address.
• Check the configured UDP and TCP ports.
• Increase the scan duration when the network is slow.
• Use a narrower subnet or port range where possible.
• Create the instance manually if broadcasts are blocked by routing or firewall rules.

Related articles

• Install and manage Connectors
• Discover instances and items
• Create and edit instances
• Create and edit items
• Create and edit mappings
• Troubleshoot Connector, instance, item, and mapping errors
• Use the Ping tool
• Configure and review system logs