Troubleshooting TIA Portal V16 Uploads with CPU Firmware 4.6

The CPU reports firmware V4.6, while the TIA Portal V16 project offers V4.4; that catalog mismatch alone does not show that the upload is corrupt. Resolve the OB1 comparison before editing or downloading, because a firmware compatibility setting and a block-content difference are separate issues.

Check the CPU identity and catalog version

Read the CPU’s exact order number and online firmware from its accessible device information, then compare them with the offline device configuration. The firmware shown online identifies the installed CPU; the version selected in the project describes the device version that the engineering project can represent.

1. Record the online order number and firmware version. Expected reading: the exact CPU identity and V4.6, matching the reported hardware.
2. Inspect the offline device configuration and the hardware catalog in V16. Expected reading: determine whether that CPU is configured as V4.4 and whether V4.6 is absent for its exact order number.
3. If the catalog lacks V4.6, check the same CPU identity in a TIA version that lists it. V4.6 device support is listed from TIA Portal V18 onward; verify the exact catalog entry before migrating or opening a working project there.

If online device information does not show V4.6, stop and resolve the identity or connection mismatch first. A project’s configured V4.4 entry does not change the CPU’s installed firmware.

Decide whether the V4.4 device representation fits the work

A project configured for an earlier firmware can represent compatible hardware running a later firmware, as long as the CPU model and supported compatibility range match. That arrangement does not expose features introduced with V4.6. Use it only when the project and the planned edit rely on functionality available to the configured V4.4 device version.

Check the project’s device configuration and the instructions or compatibility data for the exact CPU model. If the intended change depends on a V4.6 feature, move the project to an engineering version with V4.6 device support and use the matching catalog entry. If it does not, retain the V4.4 representation only after confirming that this CPU supports it. Do not infer that every CPU family accepts every earlier firmware representation.

Inspect the OB1 online and offline difference

Firmware selection and block comparison answer different questions. The first determines which device version the project can describe; the second determines whether the online OB1 and offline OB1 content match. An upload that retrieves most blocks but flags OB1 still requires a detailed comparison before download.

1. Open the detailed online/offline comparison for OB1. Expected reading: identify the specific fields or code networks reported as different.
2. Separate executable logic differences from block metadata, such as timestamps or comment-language settings. Expected reading: if only metadata differs, the executable logic may still match; if networks, instructions, or interfaces differ, treat the block as a real program discrepancy.
3. For a code difference, compare the online and offline logic in context and determine which copy is authoritative. Do not download until the intended version is clear.

A visual inspection that finds “no apparent discrepancies” is not enough when the comparison flags a difference. Use the detail view to establish whether the difference changes execution.

Compile the offline blocks and compare again

Stale or inconsistent offline compile data can make comparison results confusing. Compiling the offline project can refresh its compiled representation; compilation alone does not write those changes to the running CPU.

1. Save a separate working copy of the project.
2. Compile the relevant offline software blocks and resolve reported compile errors.
3. Reconnect to the same CPU and repeat the detailed comparison.

Expected reading: if the discrepancy was caused by stale offline compile data, the blocks should now compare as matching. If OB1 still differs, use the detailed comparison to locate the remaining logic or metadata difference and reconcile it explicitly. A successful compile is not proof that online and offline logic match.

Make the edit and verify the download

After the device representation is confirmed and OB1 has a known baseline, make the requested change in the working project. Keep the configured firmware at V4.4 only if the change uses functions available to that representation and the exact CPU supports the compatibility arrangement.

1. Edit the intended logic and compile the changed blocks. Expected reading: compilation completes without errors.
2. Run online/offline comparison again. Expected reading: only the planned change appears as a difference; unrelated blocks remain reconciled.
3. Download the intended change using the project’s supported workflow, then compare online and offline again. Expected reading: the changed logic matches the intended offline version and no unexplained OB1 discrepancy remains.

If the project requires a V4.6 feature, stop before downloading from V16 and use a TIA version with the correct device support. Do not use an apparently successful partial upload as the basis for overwriting a program whose online/offline differences remain unresolved.

Frequently asked questions