Resolving HW Config Error 256:30 Object Already Deleted in SIMATIC PCS 7 and PDM

In SIMATIC PCS 7 and SIMATIC PDM environments, STEP 7 Hardware Configuration error (256:30) 'This object has already been deleted' occurs when an engineer attempts to remove or reconfigure field devices—such as FOUNDATION Fieldbus or PROFIBUS DP/PA slaves—whose internal database cross-references have become desynchronized. Resolving this corruption requires executing 'Save and Reorganize' in SIMATIC Manager, purging orphaned PDM device instances, or reconstructing the affected fieldbus segment.

Root Causes of Database Desynchronization in STEP 7 HW Config

SIMATIC PCS 7 Hardware Configuration relies on an underlying relational database engine within STEP 7 that manages hardware catalog definitions, parameter records, and network topologies. When integrating intelligent field devices via SIMATIC PDM (such as FOUNDATION Fieldbus H1 instruments, PROFIBUS PA transmitters, or HART devices):
* The device object exists simultaneously in the HW Config station database and the PDM Process Device Plant View.
* If a deletion command is interrupted by network latency, user permission conflicts, or abnormal editor shutdown, the pointer in the PDM catalog may be removed while the graphical slave placeholder remains in HW Config (or vice versa).
* Subsequent attempts to interact with or delete the ghost object trigger error (256:30) This object has already been deleted because the database engine cannot locate the internal record ID corresponding to the selected graphical element.

Symptoms and Behavior of Error 256:30 During Device Deletion

When this error condition occurs:
* The field device icon remains visible on the PROFIBUS, PROFINET, or Fieldbus line in HW Config.
* The device table displays blank or invalid entries for I/O addresses, diagnostic addresses, and slave parameters.
* Clicking the device and pressing Delete immediately produces dialog Error (256:30) This object has already been deleted.
* Compiling the hardware configuration generates warnings regarding incomplete hardware configurations or unresolved station addresses.

Recovery Workflow 1: Save and Reorganize Project Database

The first and least invasive remediation method is executing a database rebuild through SIMATIC Manager:
1. Close HW Config, NetPro, CFC, and all other editors across all engineering clients.
2. In SIMATIC Manager, navigate to File -> Save As....
3. Select the target location and check the box With Reorganization (Slow).
4. Click OK. SIMATIC Manager performs a comprehensive defragmentation and relational integrity check, purging orphaned record IDs and repairing dangling cross-references.
5. Reopen the reorganized project, launch HW Config, and attempt to delete the ghost device. In many cases, the reorganization cleanses the orphan record and allows normal removal.

Recovery Workflow 2: SIMATIC PDM Device Purging and Subnet Reconstruction

If database reorganization does not resolve the error, the fieldbus branch must be reconstructed:
1. Purge PDM Objects:
* Open SIMATIC Manager and switch to Process Device Plant View (View -> Process Device Plant View).
* Locate the problematic field device. If present, right-click and delete it from the PDM hierarchy before touching HW Config.
2. Export Station Configuration (CFG):
* In HW Config, select Station -> Export... and save the configuration as a text-based .cfg file.
* Open the .cfg file in a text editor, locate the block defining the corrupted slave (identified by address or DP slave ID), and remove the corrupted section.
3. Subnet Reconstruction (Alternative):
* If CFG editing is unfeasible, create a temporary new PROFIBUS/PROFINET subnet in HW Config.
* Select all valid, functional field devices on the affected bus line and drag them to the new subnet.
* Delete the entire old subnet line containing the corrupted ghost device.
* Reassign the new subnet to the original communication processor (CP) or CPU master interface.
4. Compile and Save: Execute Station -> Save and Compile to regenerate clean system data blocks (SDBs).

Verification

In HW Config, verify that the bus line displays only valid, active field devices with correct address assignments.
Execute Station -> Consistency Check; confirm that no errors or dangling object warnings are reported.
Open SIMATIC PDM Process Device Plant View and confirm that all online instruments match the HW Config table.
Perform a test compilation of the AS program in SIMATIC Manager to ensure address references resolve cleanly.

Limitations and Operational Precautions

Never delete a communications processor or entire fieldbus subnet in HW Config while the automation station is in RUN mode if you intend to perform an online delta download.
Always archive the entire multiproject via File -> Archive before performing a Save As with Reorganization or editing .cfg export files.
Modifying fieldbus subnets and deleting corrupt slaves alters System Data Blocks, requiring an AS download during a plant shutdown or controlled maintenance window.

Engineer FAQ

What does STEP 7 error code (256:30) specifically indicate?
It indicates that the selected graphical object in HW Config refers to a database record ID that has already been marked as deleted or missing in the project database.
Does "Save As with Reorganization (Slow)" modify program logic?
No, reorganization compacts database files, removes deleted records, and rebuilds indexes without altering user logic or parameter values.
Why do FOUNDATION Fieldbus devices frequently trigger database desynchronization?
FF devices utilize complex dual-database management between STEP 7 HW Config and SIMATIC PDM communication servers, making them sensitive to incomplete deletion sequences.
Can I manually delete the ghost device using a database tool like Microsoft Access?
No, direct manipulation of internal .s7p or .dbf project database files is unsupported by Siemens and risks catastrophic project corruption.
What should I do if the deleted device IP address remains blocked in the network?
Reorganize the project or temporarily assign the IP to a dummy station, compile, and delete the dummy station to release the IP reservation in the subnet table.
Does deleting a ghost slave from HW Config delete its associated CFC channel drivers?
No, CFC blocks connected to the deleted slave's I/O addresses remain in the charts and will generate compilation warnings until reconnected or removed.
How can I prevent error 256:30 when decommissioning field devices?
Always delete the device from SIMATIC PDM Process Device Plant View first, save the PDM view, and then delete the slave object in HW Config.
Is an AS cold restart required after downloading reorganized hardware configuration?
If hardware changes alter the bus configuration, downloading SDBs typically requires placing the CPU in STOP mode followed by a warm restart.
Can corrupted hardware configurations cause AS-OS compilation errors?
Yes, unresolved hardware addresses prevent the OS compiler from generating correct diagnostic and channel driver tags for WinCC.
What is the purpose of exporting HW Config to a .cfg file?
Exporting generates an ASCII representation of the hardware configuration, allowing engineers to strip corrupted entries before re-importing into a clean station.

Technical References

SIMATIC STEP 7 V5.6 Hardware Configuration Manual
SIMATIC PDM The Process Device Manager Operating Manual
Siemens Industry Online Support Entry: Troubleshooting HW Config Deletion Errors (Entry ID 298469)
SIMATIC PCS 7 Fault-Tolerant Process Control Systems Manual