When the Ethernet address returns to a default after you configure the EtherCAT side, the deciding question is whether the Ethernet interface’s own address changed in its stored configuration or whether a network service reassigned it. Treat the Ethernet and EtherCAT settings as separate until the device’s interface and configuration screens show otherwise. Record the exact address before and after each change, then test persistence across a controlled power cycle.
Read the address change as a measurable symptom
The reported symptom is an Ethernet address reverting to “1.1” after another address is assigned; the complete address and subnet mask were not provided. Do not infer the omitted octets or assume “1.1” identifies a specific factory address. Record the full IPv4 address, mask, and gateway shown by the web interface, and note which device interface or protocol page displays each value.
| Quantity or setting | Where to read it | What it tells you |
|---|---|---|
| Ethernet IPv4 address, subnet mask, gateway | Device web interface and the configuration page for Ethernet | Whether the Ethernet-side values actually changed |
| EtherCAT address or network settings | EtherCAT-specific configuration page or controller configuration | Whether changes are confined to EtherCAT settings |
| Address assignment mode | Ethernet configuration and, if available, network-service settings | Whether a static setting or an address service controls the address |
| Address after restart | Web interface after a controlled power cycle | Whether the setting was stored persistently |
A changed displayed address is a configuration or address-assignment symptom, not evidence of a thermal or current-limit fault. If the web interface becomes unreachable, first check the address, subnet, and host computer’s network configuration; a changed subnet can make the device appear offline even while it is operating.
Separate Ethernet addressing from EtherCAT configuration
EtherNet/IP is an industrial communication protocol that runs over Ethernet; it is not itself a mechanism for assigning an IPv4 address. EtherCAT is a separate industrial Ethernet protocol. A device may expose settings for more than one interface or protocol, but the exact layout and persistence behavior depend on the specific model and firmware. Confirm the precise Balluff model and identify the page on which each address is set rather than treating two similarly named network fields as one value.
Address reset behavior commonly has three different causes. The Ethernet setting may not have been saved to nonvolatile configuration, an address-assignment service may provide a different address, or the unit may be restoring defaults because of a device or firmware problem. These cases look similar at first. A value that changes immediately after editing points toward an unsaved setting, an alternate page, or active address assignment; a value that changes only on restart points toward persistence or startup configuration.
Trace the transition before changing firmware
Use one controlled change at a time. Avoid changing Ethernet and EtherCAT settings together, because that makes it harder to identify which action preceded the reset.
- Record the full current Ethernet address and the displayed assignment mode. Capture the exact page or menu where the value appears.
- Confirm that the address being changed belongs to the Ethernet interface, not an EtherCAT configuration field. Record the intended address, mask, and gateway.
- Apply the Ethernet change using the device’s available save or apply control. If the interface offers a separate persistence or store action, follow the model’s instructions and verify the displayed value before leaving the page.
- Reopen the Ethernet configuration page and read the value again. Then make the EtherCAT change separately and revisit the Ethernet page.
- If the Ethernet address remains correct, perform a controlled power cycle and read the value again. Note whether the change happened during editing, after the EtherCAT change, or only after restart.
This sequence distinguishes a cross-page mix-up from a persistence failure. If an address service is enabled, determine from the device configuration and network administrator whether that service is expected to assign the address. Do not disable an active site-managed service without coordinating the intended addressing plan.
Correct the source that is replacing the address
If the value changes as soon as the EtherCAT setting is applied, return to the Ethernet page and inspect the full address and mode again. Confirm that the edit was made to the Ethernet field and committed, then repeat the isolated test. If the unit’s interface does not make it clear which network setting controls which port or protocol, stop guessing and consult the exact model’s configuration documentation.
If the value stays correct until restart, inspect the save or store procedure and the current address-assignment mode. A static address normally must be saved in the device, while a dynamic assignment can be replaced by a network service. The precise service options vary by model; read the available setting and site configuration rather than assuming DHCP, BOOTP, or any particular mode is supported.
If the interface indicates that the Ethernet value is stored, the assignment mode is correct, and the address still returns to a default, capture the sequence and compare behavior on the identified model and firmware. A firmware defect is a possible escalation path, not a diagnosis based solely on a reset. Obtain firmware and update instructions through Balluff or the authorized distributor for the exact unit; do not install firmware intended for a similar-looking product.
Verify persistence and network reachability
A successful fix has two parts: the configured Ethernet address remains unchanged after the EtherCAT settings are edited and after a controlled restart, and the device is reachable at that address from a host on a compatible subnet. Check the Ethernet configuration page after each stage, not just the browser URL or a cached session.
If the address persists but the page is unreachable, compare the host and device subnet masks and addresses, check the physical link, and connect through the intended network path. If the displayed address changes while the host remains configured for the former address, temporarily use an approved method to reach the newly assigned address and inspect the assignment mode. Keep a before/after record of address, assignment mode, firmware identification, and the exact operation that preceded each change.
Common traps when a network address reverts
Do not equate a similar Balluff device’s behavior with the behavior of the unit at hand. The discussion mentions a comparable product reverting after roughly three seconds and a firmware update resolving that case, but it does not establish that timing or fix for BNI00K6. Use the exact model and firmware identification when seeking documentation or support.
Likewise, a value shown on one page may represent a different interface or protocol setting, and a reboot can reveal a setting that was never committed. Changing several network fields at once obscures the cause. Separate the edits, observe when the value changes, and use the measured before/after address to decide whether to investigate configuration, address assignment, persistence, or firmware.
Frequently asked questions
Why does the Ethernet IP address change after I configure EtherCAT?
First verify that the two values belong to the intended interface and configuration pages. Apply the Ethernet change alone, reread it, then change EtherCAT and reread Ethernet to isolate the operation that triggers the reset.
Why does the address return after a power cycle?
The Ethernet setting may not have been stored, or an address-assignment service may provide a different value at startup. Check the Ethernet save/store procedure and assignment mode, then compare the displayed address before and after restart.
How do I keep the Balluff Ethernet address static?
Use the Ethernet configuration page for the exact model, set the intended address and related network values, select the supported static mode if available, and commit the change using the documented procedure. Verify the value after reopening the page and after a controlled restart.
Could firmware make the address reset?
A firmware defect can cause configuration problems, but a reset alone does not identify firmware as the cause. Confirm the full model and firmware, rule out an incorrect page, assignment mode, and unsaved change, then ask Balluff or its authorized distributor to assess the appropriate firmware.
What should I record before contacting support?
Record the complete before-and-after Ethernet address, mask and gateway, assignment mode, firmware identification, the exact change made, and whether the reset occurs immediately or only after restart. Stop changing network settings and escalate to Balluff or the authorized distributor if the correct model-specific save procedure and assignment mode still produce a repeatable reset.
Stop and escalate if the address repeatedly returns to a default after the model-specific save procedure, or if you cannot distinguish the Ethernet and EtherCAT settings safely. Provide the recorded transition and exact model and firmware identification to Balluff or its authorized distributor.