I would like to ask whether it is technically supported (and practically achievable) to combine CODESYS Master Redundancy with EtherCAT ring (loop) redundancy in the same system.
System setup
CODESYS version:
CODESYS 3.5.21.40
CODESYS Control SL for Weidmuller u-OS-4.12.2.0
Controllers (Masters):
Weidmuller UC20-M4000 ×2, configured as Active / Standby using CODESYS redundancy
EtherCAT Slaves:
Weidmuller UR20-FBC-EC ×3, supporting EtherCAT ring / line break detection
Topology:
EtherCAT ring (loop)
Main question
Is it officially supported to use:
・CODESYS PLC/Master redundancy (Active/Standby)
and
・EtherCAT ring topology (for cable redundancy)
at the same time?
Expected behavior
Our expectation is:
・When the Active PLC fails, the Standby PLC becomes Active
・The Standby PLC then takes over the role of EtherCAT Master
・EtherCAT communication is re-established
・I/O control continues after reinitialization (a short interruption is acceptable; no strict bumpless requirement)
We do not expect completely seamless / zero-cycle switchover, but we want to understand:
・Whether this combination is supported by design
・Or whether there are known limitations or restrictions when EtherCAT ring mode is used together with Master　redundancy
Clarification
At this stage, the question is mainly about feasibility and support, not about a specific error message yet.
Any official guidance, limitations, or real-world experience would be greatly appreciated.
Thank you in advance.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Yes, this works (at least we have it running with Wago PLC and Beckhoff I/O), but the concept works. You need 2 PLC's with at leat 3 network interfaces. And 2 switches (can be unmanaged). See the attached simple diagram for the solution.
Hello,
I would like to ask whether it is technically supported (and practically achievable) to combine CODESYS Master Redundancy with EtherCAT ring (loop) redundancy in the same system.
System setup
CODESYS version:
CODESYS 3.5.21.40
CODESYS Control SL for Weidmuller u-OS-4.12.2.0
Controllers (Masters):
Weidmuller UC20-M4000 ×2, configured as Active / Standby using CODESYS redundancy
EtherCAT Slaves:
Weidmuller UR20-FBC-EC ×3, supporting EtherCAT ring / line break detection
Topology:
EtherCAT ring (loop)
Main question
Is it officially supported to use:
・CODESYS PLC/Master redundancy (Active/Standby)
and
・EtherCAT ring topology (for cable redundancy)
at the same time?
Expected behavior
Our expectation is:
・When the Active PLC fails, the Standby PLC becomes Active
・The Standby PLC then takes over the role of EtherCAT Master
・EtherCAT communication is re-established
・I/O control continues after reinitialization (a short interruption is acceptable; no strict bumpless requirement)
We do not expect completely seamless / zero-cycle switchover, but we want to understand:
・Whether this combination is supported by design
・Or whether there are known limitations or restrictions when EtherCAT ring mode is used together with Master　redundancy
Clarification
At this stage, the question is mainly about feasibility and support, not about a specific error message yet.
Any official guidance, limitations, or real-world experience would be greatly appreciated.
Thank you in advance.
Yes, this works (at least we have it running with Wago PLC and Beckhoff I/O), but the concept works. You need 2 PLC's with at leat 3 network interfaces. And 2 switches (can be unmanaged). See the attached simple diagram for the solution.