Resolving LOGO! Soft Comfort V8 Ethernet Blank Connection Issue

Problem Overview

Siemens LOGO! Soft Comfort V8 and V8.1 occasionally fail to populate the Online connection dialog with the host PC's Ethernet adapter, leaving the Ethernet interface field blank. The software still detects the local service interface (USB) and the COM ports but never lists the wired or wireless LAN adapter that other Windows applications use without issue. The fault survives an in-place repair install, a complete uninstall/reinstall, and even a clean Windows image with the exact same build number that previously worked, which points at a registry-backed configuration file and a driver-stack problem rather than a corrupted LSC installation.

Symptom summary:

• Ethernet dropdown in Tools → Options → Interface is empty.
• Online → Connect to LOGO! fails with timeout to 192.168.0.1 or the configured S7-style IP.
• Same LOGO! Soft Comfort V8.1 install on a different PC detects the Ethernet adapter correctly.
• Windows network stack, ipconfig /all, and the Network and Sharing Center show the adapter as enabled with a valid IPv4 address.

Root Cause Analysis

LOGO! Soft Comfort V8.x stores the user-selected communication port in an INI file located at:

C:\Users\<username>\.LOGOcomfort8.x\Application.ini

The relevant block looks similar to:

[Connection]
Port=COM1
Baudrate=19200
Protocol=LOGO!
Timeout=2000

On a fresh install the Port= entry is hard-coded to COM1. If you are connecting to a LOGO! 8 via Ethernet, this is invalid: LSC will not show the LAN adapter in the GUI because its internal cache still says you want COM1. The same value is also written by the registry mirror in:

HKEY_CURRENT_USER\Software\Siemens\LOGOcomfort\8.x\Connection

Two conditions must both be present for the dropdown to populate correctly:

1. The INI must reference the Windows adapter name (the friendly name, e.g. Intel(R) Ethernet Connection I219-V), not COM1.
2. The underlying NDIS driver for that adapter must expose a Winsock-compatible socket layer that LSC's LOGOCom.dll can bind to.

When either condition fails, the GUI stays blank even though the OS reports the network as operational.

Secondary Cause: PCI Simple Communications Controller Driver

Devices in the System Devices tree that Windows classifies as PCI Simple Communications Controller (vendor 8086 / 0A0E, 0A1E, 9D31 and similar Intel ME/AMT chipsets) often ship without a vendor driver on a clean Windows 11/10 install. The missing driver disables the Intel Management Engine Interface and can indirectly break the binding chain that LSC uses to enumerate LAN adapters, particularly on Intel NICs that share the same PCI function. The fix is to install the chipset INF package from the OEM or directly from Intel's driver catalog before relaunching LSC.

Affected Versions and Components

Prerequisites

Before you edit any file, capture the following so the procedure is repeatable and reversible.

1. Active administrator account on Windows 10 22H2 or Windows 11 23H2/24H2.
2. The exact Windows adapter name as it appears in Settings → Network & Internet → Status → Change adapter options. Right-click the adapter and choose Rename if needed to remove special characters; LSC's INI parser can choke on apostrophes, em-dashes, and the ampersand.
3. A static IPv4 address on the PC, e.g. 192.168.0.10, with subnet 255.255.255.0, on the same subnet as the LOGO! 8BM or LOGO! 8.3 (default 192.168.0.1).
4. Direct Ethernet cable between the PC and the LOGO! (or a managed switch in the same VLAN). Avoid USB-C hubs with built-in Ethernet on the first attempt; they are a common false positive.
5. Backup copy of the current INI: copy C:\Users\%USERNAME%\.LOGOcomfort8.x\Application.ini %USERPROFILE%\Desktop\Application.ini.bak.

Solution Method 1: Edit Application.ini Directly

This is the deterministic fix for the blank Ethernet dropdown.

1. Close every instance of LOGO! Soft Comfort V8.x. Verify with Task Manager → LOGOCom.exe and LOGOcomfort.exe.
2. Open %USERPROFILE%\.LOGOcomfort8.x\. On Windows 10/11 the leading dot means the folder is hidden; in Explorer enable View → Hidden items or paste the full path into the address bar.
3. Open Application.ini in Notepad (do not use Word/Wordpad, they save in rich-text).
4. Locate the line Port=COM1 and replace it with the Windows adapter name in quotes-free form, e.g.:

   Port=Intel(R) Ethernet Connection I219-V

   If you are on Wi-Fi, use the WLAN adapter name, e.g. Port=Intel(R) Wi-Fi 6 AX201 160MHz.
5. Set the rest of the block to the Ethernet profile:

   [Connection]
   Port=Intel(R) Ethernet Connection I219-V
   Baudrate=100000000
   Protocol=LOGO!
   Timeout=3000
   RemoteIP=192.168.0.1
   RemotePort=8443

   RemoteIP must match the LOGO!'s configured IP. RemotePort is 8443 for HTTPS access on LOGO! 8.3 BM and 102 for classic S7 frames on LOGO! 8.
6. Save the file. Confirm it is saved as ANSI encoding (Notepad: Save As → Encoding: ANSI). UTF-8 with BOM works; UTF-8 without BOM has been observed to corrupt the Port= token on a German LSC build.
7. Right-click the desktop shortcut to LOGO! Soft Comfort and choose Run as administrator. UAC elevation is required to bind to the socket LSC uses for LOGO! 8BM.
8. Open Tools → Options → Interface. The Ethernet dropdown is now populated with the adapter name from the INI.

Solution Method 2: Repair the Driver Stack

Use this when Method 1 succeeds in populating the dropdown but the online connection still times out. A mismatched or missing network driver is the most frequent second-layer cause.

1. Open Device Manager and expand Network Adapters. Note any device flagged with a yellow bang.
2. Check for an unidentified PCI Simple Communications Controller under System Devices. If present, install the matching chipset driver from the laptop/OEM vendor. Lenovo: support.lenovo.com. HP: support.hp.com/drivers. Intel standalone: Intel Download Center.
3. On the network adapter, right-click → Update driver → Search automatically for drivers. If Windows reports a generic Realtek PCIe GbE Family Controller or Intel(R) PRO/1000 from the inbox driver catalog, force the vendor driver using pnputil /add-driver <path>\*.inf /subdirs /install.
4. Reboot, then run ncpa.cpl and confirm the adapter is Enabled, has a green line in the icon, and reports Connected.
5. Open Command Prompt as administrator and run:

   netsh winsock reset
   netsh int ip reset
   ipconfig /flushdns
   ipconfig /release & ipconfig /renew

6. Relaunch LSC and repeat Method 1. The dropdown should now both be populated and functionally reach the LOGO! on its IP.

Step-by-Step Validation with Pings and ARP

ping 192.168.0.1
arp -a 192.168.0.1
tracert 192.168.0.1

You must get replies in < 1 ms. If the LOGO! replies only to ping but not to LSC, the firewall is the next suspect. Open Windows Defender Firewall → Inbound Rules and confirm LOGOcomfort.exe is allowed on the active profile (Domain/Private). LSC V8.x does not auto-create this rule on first run; the initial connection attempt may trigger an allow-prompt that gets dismissed.

Solution Method 3: USB-to-Ethernet Adapter Bypass

If the on-board NIC has a known driver defect (e.g. some I225-V revisions B2 and B3 under load) and Method 2 does not stabilize the link, add a discrete USB-3.0-to-1000BASE-T adapter and bind LSC to it. Field-tested parts:

Plug the USB-Ethernet in, wait for the OS to bind, then re-open Application.ini and replace the Port= value with the new adapter's friendly name, e.g. Port=USB Ethernet/RNDIS Gadget or Port=Realtek USB GbE Family Controller. Restart LSC and verify with Online → Connect to LOGO!.

Network Adapter Naming Rules for Application.ini

The Port= token must match what the OS reports, character-for-character, with these constraints:

• Parentheses around the chip family are required: Intel(R) not Intel.
• Hyphens, slashes, and ampersands are passed through.
• Apostrophes in manufacturer names (e.g. Marvell's Yukon) require escaping by removing the apostrophe from the NIC name, not by escaping it in the INI.
• Maximum string length is 64 characters. Rename long names to fit.

Verification Steps

1. In LSC, open Tools → Options → Interface. Confirm the Ethernet adapter name appears in the dropdown and is selected.
2. Click Online → Connect to LOGO!. The status bar should read Online within 2-3 seconds.
3. Press F1 on the LOGO! to enter transfer mode if the device is in run. LSC will report Transfer completed after a project upload/download.
4. Open a Command Prompt and run netstat -an | findstr :8443. A ESTABLISHED entry from 192.168.0.10 to 192.168.0.1:8443 confirms the socket is open.
5. Close LSC, re-open it without admin, and confirm the connection still works. If not, the firewall rule is the cause; re-allow the LSC binary.

Common Pitfalls and Anti-Patterns

Windows Network Configuration Reference

For general Windows network issues independent of LSC, follow the official Microsoft Fix Ethernet connection problems in Windows guide, which covers cable testing, modem/router power-cycle, NIC reset, and driver rollback. LSC inherits any underlying Windows fault, so this guide is the baseline.

LOGO! Soft Comfort Communication Profile Reference

Field Commissioning Checklist

1. PC: static IP 192.168.0.10/24, gateway empty is fine for direct link.
2. LOGO!: static IP 192.168.0.1/24, mask 255.255.255.0, no client gateway.
3. Cable: shielded Cat 5e or better, < 50 m to first device.
4. Application.ini: Port=<exact adapter name>, RemoteIP=192.168.0.1, RemotePort=8443 or 102.
5. Windows Firewall: LOGOcomfort.exe allowed on Private profile.
6. LSC: run as administrator at least once to populate WinSock catalog.
7. Validate: netstat -an | findstr :8443, ping 192.168.0.1 -t.

FAQ