Using POSIX realtime

sudo apt remove ethercat-master ethercat-dkms
sudo apt install ethercat-master ethercat-dkms
# edit /etc/ethercat.conf again

debian@plasma:~$ sudo service ethercat status
● ethercat.service - EtherCAT Master Kernel Modules
     Loaded: loaded (/lib/systemd/system/ethercat.service; enabled; preset: enabled)
     Active: active (exited) since Thu 2025-05-08 20:32:57 CEST; 7min ago
    Process: 78578 ExecStart=/usr/sbin/ethercatctl start (code=exited, status=0/SUCCESS)
   Main PID: 78578 (code=exited, status=0/SUCCESS)
        CPU: 25ms

maj 08 20:32:57 plasma systemd[1]: Starting ethercat.service - EtherCAT Master Kernel Modules...
maj 08 20:32:57 plasma systemd[1]: Finished ethercat.service - EtherCAT Master Kernel Modules.

auto enp2s0
iface enp2s0 inet manual
        hardware-irq-coalesce-rx-usecs 0
        pre-up /sbin/ifconfig $IFACE up
        post-down /sbin/ifconfig $IFACE down

4: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether c4:62:37:06:66:54 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::c662:37ff:fe06:6654/64 scope link
       valid_lft forever preferred_lft forever

2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 80:ee:73:fd:0f:8b brd ff:ff:ff:ff:ff:ff
    inet6 fe80::d771:e69b:b8c8:1f5e/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

* The master decides, if it wants to use the device for EtherCAT operation,
 * or not. It is important, that the offered net_device is not used by the
 * kernel IP stack. If the master, accepted the offer, the address of the
 * newly created EtherCAT device is returned, else \a NULL is returned.

sudo cp /usr/sbin/ethercatctl ectl
# ... edit ectl and add debug_level=1 to this line a shown around line 126 in ectl

    # load master module
    if ! ${MODPROBE} ${MODPROBE_FLAGS} ec_master \
            main_devices="${DEVICES}" backup_devices="${BACKUPS}" debug_level=1; then
        exit 1
    fi

# Make executable
chmod +x ectl
# and start the ethercat master, then reset debug level to 0. It produces a lot of info
sudo ./ectl start
ethercat debug 0

sudo dmesg

00:00.0 Host bridge: Intel Corporation Device 461c
    DeviceName: Onboard - Other
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Device 4164
00:02.0 VGA compatible controller: Intel Corporation Alder Lake-N [UHD Graphics]
    DeviceName: Onboard - Video
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N [UHD Graphics]
    Kernel driver in use: i915
    Kernel modules: i915
00:14.0 USB controller: Intel Corporation Alder Lake-N PCH USB 3.2 xHCI Host Controller
    DeviceName: Onboard - Other
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCH USB 3.2 xHCI Host Controller
    Kernel driver in use: xhci_hcd
    Kernel modules: xhci_pci
00:14.2 RAM memory: Intel Corporation Alder Lake-N PCH Shared SRAM
    DeviceName: Onboard - Other
00:16.0 Communication controller: Intel Corporation Alder Lake-N PCH HECI Controller
    DeviceName: Onboard - Other
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCH HECI Controller
    Kernel driver in use: mei_me
    Kernel modules: mei_me
00:17.0 SATA controller: Intel Corporation Alder Lake-N SATA AHCI Controller
    DeviceName: Onboard - SATA
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N SATA AHCI Controller
    Kernel driver in use: ahci
    Kernel modules: ahci
00:1c.0 PCI bridge: Intel Corporation Alder Lake-N PCI Express Root Port
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCI Express Root Port
    Kernel driver in use: pcieport
00:1c.1 PCI bridge: Intel Corporation Alder Lake-N PCI Express Root Port
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCI Express Root Port
    Kernel driver in use: pcieport
00:1d.0 PCI bridge: Intel Corporation Alder Lake-N PCI Express Root Port
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCI Express Root Port
    Kernel driver in use: pcieport
00:1f.0 ISA bridge: Intel Corporation Alder Lake-N PCH eSPI Controller
    DeviceName: Onboard - Other
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCH eSPI Controller
00:1f.3 Audio device: Intel Corporation Alder Lake-N PCH High Definition Audio Controller
    DeviceName: Onboard - Sound
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N PCH High Definition Audio Controller
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd_hda_intel, snd_sof_pci_intel_tgl
00:1f.4 SMBus: Intel Corporation Alder Lake-N SMBus
    DeviceName: Onboard - Other
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N SMBus
    Kernel driver in use: i801_smbus
    Kernel modules: i2c_i801
00:1f.5 Serial bus controller: Intel Corporation Alder Lake-N SPI (flash) Controller
    DeviceName: Onboard - Other
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Alder Lake-N SPI (flash) Controller
01:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-LM (rev 04)
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Ethernet Controller I226-LM
    Kernel driver in use: igc
    Kernel modules: igc
02:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-LM (rev 04)
    Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Ethernet Controller I226-LM
    Kernel driver in use: igc
    Kernel modules: igc
03:00.0 Non-Volatile memory controller: Transcend Information, Inc. NVMe PCIe SSD 110S/112S/120S/MTE300S/MTE400S/MTE652T2 (DRAM-less) (rev 03)
    Subsystem: Transcend Information, Inc. NVMe PCIe SSD 110S/112S/120S/MTE300S/MTE400S/MTE652T2 (DRAM-less)
    Kernel driver in use: nvme
    Kernel modules: nvme