Migrating LOGO! 0BA6/0BA7 to 0BA8: Soft Comfort V8 Upgrade Guide

Overview: Why a Migration Path Matters

The Siemens LOGO! 0BA8 generation introduced a fundamentally redesigned hardware platform, an integrated Ethernet interface, a 6-line graphic display, and an expanded I/O count. Because the 0BA8 base module is electrically and mechanically incompatible with the 0BA6 and 0BA7 expansion bus, the migration is rarely a drop-in replacement. The companion PC tool, LOGO! Soft Comfort V8 (LOGOSoftComfortV8.x), supports projects from 0BA0 through 0BA8 but enforces a hardware device type match between the project and the target module. This reference consolidates the upgrade path, the compatibility constraints, and the verification steps required to port an installed LOGO! 0BA6 or 0BA7 application onto a 0BA8 base module without losing program logic.

Prerequisites Before the Upgrade

1. Licensed or DVD copy of LOGO! Soft Comfort — incremental installation is more reliable when performed from the full DVD (V6 → V7 → V8) rather than chained over-the-top updates.
2. Administrator rights on the PC — required for the USB driver, the Ethernet service, and the registry entries that map the .LSC and .LUF file types.
3. Backup of all existing .LSC and .LUF files — the V8 installer does not always migrate user data folders cleanly. Locate them under C:\Users\<user>\Documents\LOGO! Soft Comfort\ (Windows 7/10/11) or Documents and Settings\<user>\My Documents\LOGO! Soft Comfort\ (Windows XP).
4. SD card or USB cable for the target 0BA8 — the Ethernet connection requires the PC and the 0BA8 to be on the same subnet (default IP 192.168.0.1, subnet 255.255.255.0).
5. Project documentation — record the current hardware configuration (number and type of DM8/AM2/AM2 AQ modules) so the 0BA8 can be reconfigured to a functionally equivalent layout.

Software Upgrade Path: V6 → V7 → V8

Soft Comfort V8 can be installed directly on a system that already has V6 or V7, but Siemens historically distributed V8 as an upgrade installer that expects a base version already present. When the V8 installer is run on a machine that has V6 (and not V7), it may fail to migrate the user profile or to register file associations. The reliable sequence is:

1. Install or update to LOGO! Soft Comfort V7 (full DVD build, e.g., LOGOSoftComfortV7.0.exe or later service pack). Confirm the V7 projects open and simulate correctly.
2. Install LOGO! Soft Comfort V8 (LOGOSoftComfortV8.0.exe or the current service pack) on top of V7. Register the product with the supplied license key when prompted.
3. If the V8 installer aborts with an MD5 or file-integrity error, copy the V8 .LUF (Logo Update File) to a fresh directory such as D:\Updates\LOGO_V8\ and re-launch the installer, selecting the new directory as the source.

When chained over-the-top updates produce corrupted menus or "missing DLL" errors, the standard field remedy is to delete stale .LUF cache files from the user's local profile before the re-install:

On a clean PC, the same V8 .LUF can be applied directly, skipping the V6/V7 step. Soft Comfort V8 reads project files (.LSC, .LSCX, .LGO) from all prior versions. The reverse is not true: a project saved in V8 cannot be opened in V7 or earlier because V8-only function blocks (network FB, web server FB) are not recognized.

Hardware Compatibility Matrix: 0BA6/0BA7 vs. 0BA8

The 0BA8 base module is electrically incompatible with the 0BA6/0BA7 expansion bus. This means every DM8, DM16, AM2, AM2 RTD, and AM2 AQ module that was sitting on the 0BA6 or 0BA7 must be physically replaced if the application requires more I/O than the 0BA8 base provides. The mapping below covers the most common 0BA6/0BA7 layouts.

Base Module Differences That Affect Programs

Code Migration: Step-by-Step Procedure

Program code migrates cleanly from 0BA6/0BA7 to 0BA8 because Soft Comfort V8 retains the same FBD editor and the same standard function block library. The work that must be done is in the device configuration, not in the logic.

1. Open the V6 or V7 project in Soft Comfort V8. The conversion dialog prompts to confirm the source generation; click Convert. A backup of the original file with the suffix _backup.LSC is written to the project folder.
2. Set the device type in the toolbar: select Tools → Select Hardware → LOGO! 0BA8 (and the matching base-module variant, e.g., LOGO! 230RCE for the 115/230 V AC relay version). Saving the project at this point is what actually writes the new device descriptor to the .LSC.
3. Re-add the I/O blocks. Any input or output that referenced a DM8/AM2 module on 0BA6/0BA7 will be flagged in the Info Window with a warning such as "Block B003 references I9 which is not available on LOGO! 0BA8". Drag the I/O connector onto the I-block to re-attach it to an input that exists on the 0BA8 (I1 – I8 for digital, AI1 – AI4 for the 24 V analog inputs).
4. Verify analog scaling. Because the 0BA8 exposes AI3 and AI4 on physical terminals I7 and I8, an 0BA7 program that used AI1/I7 will continue to read I7, but its meaning is now AI3. If the original code used the 0BA7 "two analog input" feature on a 230 V base module (where AI1/AI2 are disabled), it must be re-mapped to a 24 V base module to keep the inputs alive.
5. Remove or replace V8-only blocks. If the V7 project was opened in V8 and the user accidentally inserted a V8-only block (e.g., Network Input/Output, Web Server), and the goal is to load the project back into a 0BA7 for the parallel-production line, those blocks must be deleted before saving for the 0BA7.
6. Simulate with Tools → Simulation (Start). The simulator in V8 enforces the device type: if the project is set to 0BA8, the analog input count and the network FBs are available. If the simulator raises "Block count exceeds device limits", the project is still tagged to 0BA6/0BA7 — repeat step 2.
7. Compile and check the Info Window for warnings. A clean conversion shows zero warnings. Common warnings and their fixes are listed in the troubleshooting matrix below.
8. Transfer to the 0BA8 via Ethernet, USB, or microSD. The Ethernet path is the new default in V8: Tools → Transfer → PC ↔ LOGO!, enter the IP address (192.168.0.1 by default), and click Send.

Common Conversion Warnings and Remedies

Display and Front-Panel Differences

The 0BA6 and 0BA7 share a 4-line × 12-character text LCD with amber backlight and six navigation keys. The 0BA8 uses a 6-line × 16-character graphic LCD with white backlight and the same six navigation keys plus a dedicated ESC key. Program logic that drives a Message Text block behaves identically: any text entered in V7 will be rendered on the 0BA8. Program logic that targets a particular line of the display (a V8 feature) cannot be loaded on 0BA6/0BA7 and must be removed for any project that is still shared with the older devices.

Phaseout and Spare-Parts Planning

Siemens formally announced that the 0BA6 and 0BA7 series would continue to be supplied for at least one year after the 0BA8 release, after which a product-phaseout process would begin. Field planning should therefore account for:

• Spare-module buffer. Stock at least 12 months of DM8/AM2 spares for each 0BA6/0BA7 site. The phaseout window has historically aligned with the introduction of the next-generation 0BA9 device, which would force an all-new migration.
• Project duplication. Keep the master program in Soft Comfort V7 and a working copy in V8. The 0BA6/0BA7 hardware will not accept a V8-only program, but the V8 version can always be re-saved as V7 by selecting 0BA7 as the device type — provided the project has no V8-only function blocks.
• Newsletter subscription. Siemens LOGO! newsletters (linked from the LOGO! support page) carry the formal phaseout dates, last-time-buy deadlines, and successor-product announcements. These dates are not posted in the manuals and are not always reflected in the catalog.

Verification Procedure After the Transfer

1. From the LOGO! 0BA8 main menu, navigate to Program → Card → Copy LOGO → Card and confirm that the program on the microSD card is identical to what was sent. This guards against a partial transfer caused by a loose Ethernet cable.
2. Cycle power to the 0BA8 with the program loaded. Watch the status line on the display — if it shows "No program" or "Program error", the device type in the project is wrong, and Soft Comfort V8 must be used to re-send the correct descriptor.
3. Force each digital input and verify the corresponding I-flag in LOGO! menu → Parameters → I/O Status lights up. The I-flag should toggle within 20 ms of the input change; slower response indicates a wiring or scan-time issue unrelated to the migration.
4. For each analog input, apply a known reference (e.g., 10.00 V from a calibrator) and read back the engineering unit in the project (e.g., on a display block). The 0BA8 ADC has the same 10-bit resolution and 0–10 V range as the 0BA7, so values within ±2 LSB of the 0BA7 reading are expected.
5. Trigger every output and verify the contactor or actuator responds. If a relay output sticks, check the contact rating — the 0BA8 relay is rated 10 A continuous per normally-open contact, identical to 0BA7, but the inductive load derating curve is stricter above 6 A.
6. Save the verified program back to the PC as a .LSC archive. Tag the file with the cabinet ID and the date so the next migration has a known-good starting point.

Troubleshooting Matrix

Field-Engineer Notes

• Direct substitution is not a safe assumption. Siemens' own product-communication explicitly states that the 0BA8 is "not 100 % compatible" with 0BA6 and 0BA7. The 0BA6/0BA7 must be treated as a separate spare-parts line until the phaseout is complete.
• Code reuse is generally safe. Field experience shows that V6 and V7 programs open and simulate in V8 without errors, provided the device type is changed and the I/O map is reconciled.
• Pre-version your project files. Save the V6/V7 source untouched in a "legacy" subfolder. The conversion to V8 is one-way at the project level; re-saving a V8 file as V7 only works if no V8-only blocks are present.
• Keep the install media. The DVD (or original .LUF) is required to perform a clean re-install if a Windows feature update breaks the V8 installer's COM registration.
• Document the hardware suffix. The 0BA8 article numbers (6ED1 052-xxx08-0BA8) are the only safe substitutes for the 0BA6/0BA7 (-0BA2) variants. Cross-generation order numbers are not interchangeable.