Resolving Disabled Download Option in STEP 7 Simatic Manager V5.5

Problem Overview

Engineers working with Siemens STEP 7 SIMATIC Manager V5.5 (including the SP2, SP3, SP4, SP5, and final SP6 distributions) occasionally encounter a condition where the Download command on the toolbar, the PLC → Download menu, or the right-click context menu becomes disabled (greyed out) while editing FCs (Function blocks), FBs (Function Blocks), OBs (Organization Blocks), or DBs (Data Blocks). The same condition is sometimes reported for entire S7 programs where no block, including system blocks, can be downloaded to the target CPU.

The symptom is typically:

• The Download icon in the SIMATIC Manager toolbar is inactive.
• The PLC → Download menu is unavailable.
• Right-clicking on a block in the Program blocks folder does not present a Download option.
• Hardware download (CPU → Download to Programming Device) is also blocked when the S7 program is unassigned.

Unlike a typical online/offline state mismatch, the disabled button is not cleared by toggling the Online view, by selecting the CPU, or by changing the PG/PC interface. The root cause is structural and is resolved by correcting the project metadata rather than the runtime state.

Root Cause Analysis

STEP 7 V5.5 and the integrated SIMATIC Manager tolerate two distinct project classes with fundamentally different engineering workflows:

When a STEP 7 project is created and then opened, edited, or saved by PCS 7 components (or vice versa), the Project Type field stored in the project's .s7p metadata is rewritten to PCS 7. SIMATIC Manager will then hide the standard STEP 7 download controls in favor of the PCS 7 download workflow, which routes through the Plant View, the master data library, and the CFC/SFC chart objects. The end user sees this as a disabled button in the STEP 7 view.

Two additional root causes can produce an identical symptom on standard STEP 7 projects:

1. Unassigned S7 program — the FC is located in a Program container that is not part of any SIMATIC 300/400 Station in the project tree.
2. Missing PG/PC interface assignment — the project's Set PG/PC Interface points to None, so SIMATIC Manager suppresses download actions because no route to a target CPU can be defined.

Siemens documents this behavior in the FAQ entry 19267653 on the Siemens Industry Online Support portal, which is the primary reference for the PCS 7 / STEP 7 project type switch.

Diagnostic Procedure

Before applying a fix, confirm which of the three root causes is in effect. Use the following ordered diagnostic tree.

1. Open the project properties. In SIMATIC Manager, select the project root node and press Alt+Enter or right-click → Object Properties. The Project Type field is displayed on the first tab.
2. Inspect the project tree. Confirm whether the Program blocks folder is located under a SIMATIC 300 Station, SIMATIC 400 Station, or SIMATIC PC Station object. An S7 program that is positioned at the project root or in a Sources container is considered unassigned.
3. Check the PG/PC interface. From the menu bar, select Options → Set PG/PC Interface. Confirm that the access point S7ONLINE is bound to a valid adapter (e.g. TCP/IP → Network Card (RFC1006) for MPI/TCP routed access, or PC Adapter (MPI) for USB-to-MPI).
4. Attempt a partial recreation. If the previous checks are inconclusive, create a new blank STEP 7 project, copy the affected FC into the new project's S7 program, and test the download button. If the button is enabled in the new project, the original project contains corrupted metadata that must be repaired with a re-organization save.

Solution 1 — Switch Project Type from PCS 7 to STEP 7

This is the resolution for the most common cause and is documented in Siemens FAQ 19267653.

1. Open the project in SIMATIC Manager V5.5.
2. Right-click the project root (the topmost item showing the project name).
3. Select Object Properties.
4. In the General tab, locate the Project Type dropdown.
5. Change the selection from PCS 7 to STEP 7.
6. Click OK. SIMATIC Manager will prompt to save and reopen the project.
7. After reopening, the Download toolbar icon becomes active and the PLC → Download menu is restored.

If the field is greyed out and cannot be changed, the project has been digitally signed or locked by a PCS 7 master data library. In that case, close the project, take a backup copy, then delete the file <project>\<project>.s7p.lock if present and retry. The lock file is created when the Commissioning or Change Log functionality in PCS 7 is active.

Solution 2 — Reassign the S7 Program to a Station

If the project type is already STEP 7 but the FC is part of a Program that is not nested under a station object, the download button will also be disabled. This is by design: SIMATIC Manager only permits download for blocks that are part of a programmed module assigned to a configured station.

1. Open the SIMATIC Manager project view and identify the S7 program that contains the FC.
2. Right-click the S7 program and choose Cut.
3. Navigate to the target SIMATIC 300 Station or SIMATIC 400 Station in the project tree.
4. Right-click the station and select Paste. The S7 program is inserted as a child of the station.
5. Confirm that the Hardware object inside the station contains a CPU whose MPI/DP/PN address matches the physical target.
6. Select the FC and verify that the Download button is now enabled.

For projects with a single S7 program that has been detached from a station, dragging the program onto the station with the mouse performs the same reassignment and updates the S7PROG\PROGRAM reference inside the project's master data file.

Solution 3 — Compile Blocks and Reorganize the Project

If the project type and S7 program placement are correct but the download button is still disabled, the project file structure has internal inconsistencies. Two recovery actions are available.

Block Recompile

1. Open the S7 program and select the Program blocks container.
2. Right-click → Compile (or Compile and Download Objects for a selective compile).
3. Confirm any prompts regarding interface changes between FBs and their instance DBs.
4. Recompile writes corrected BSEND/SFR time stamps and resolves most orphaned block references.

Save As with Reorganization

1. From the menu bar, select File → Save As.
2. Enter a new project name. SIMATIC Manager will offer the option With reorganization (slow).
3. Enable With reorganization (slow) and click OK.
4. Reorganization rebuilds the Global, Symbols, and OMSTRT subsystem files, eliminating duplicate or orphaned entries that can cause menu suppression.

Solution 4 — Verify and Reset the PG/PC Interface

SIMATIC Manager suppresses the Download action when the S7ONLINE access point cannot resolve a route to a target. The Set PG/PC Interface dialog is the control surface for this binding.

1. Open Options → Set PG/PC Interface.
2. For the S7ONLINE access point, select the appropriate adapter:
   • TCP/IP → Network Card (RFC1006) for Ethernet-based routing (PN or routed MPI/DP via NET).
   • PC Adapter (MPI) or PC Adapter (Auto) for the USB-to-MPI/DP cable (order number 6ES7 972-0CB20-0XA0).
   • CP5611 (MPI) or CP5613 (MPI) for legacy PCI communication processors.
3. Click Diagnostics to verify that the adapter is detected and the bus is reachable.
4. Re-open the project. The download button is enabled when the S7ONLINE route is valid.

Setting the access point to None produces the symptom: SIMATIC Manager will still display the project tree and allow offline editing, but every download control remains disabled.

Verification Procedure

After applying any of the four solutions above, perform the following verification sequence before reconnecting to a live process.

1. Toolbar check. Select the affected FC. The Download icon in the SIMATIC Manager toolbar must change from greyed-out to active.
2. Menu check. Confirm that PLC → Download is selectable and is not followed by an Error: No target station found prompt.
3. Online view. Press Ctrl+L or select PLC → Online. SIMATIC Manager must display the Online view of the project and resolve the target CPU's order number, firmware version, and slot configuration.
4. Block consistency. In online view, compare the offline and online block time stamps. Mismatched time stamps indicate the FC was edited offline and a download is required; matching time stamps indicate the offline and online blocks are already synchronized.
5. Test download to PLCSIM. Open S7-PLCSIM V5.4 SP8 (or the version bundled with the V5.5 STEP 7 distribution) and use PLC → Download with the simulated CPU selected. A successful download confirms the project, the interface, and the program placement are all correct.

Related Project Properties That Affect Download Behavior

The Object Properties dialog contains several fields that interact with the download state. Engineers should be aware of the following.

Preventive Measures

To avoid recurrence, apply the following engineering practices on STEP 7 V5.5 projects.

• Segregate STEP 7 and PCS 7 projects. Do not open a standard STEP 7 project with the PCS 7 engineering components. The PCS 7 installer rewrites the project type on first save.
• Use a master template. Create a project template with the correct Project Type and store it in a version-controlled directory. Clone the template for every new project instead of converting existing ones.
• Lock the project type. Set the .s7p file as read-only in the file system (after saving) to prevent the PCS 7 components from rewriting the metadata. Remove the read-only flag only when a controlled PCS 7 conversion is required.
• Document the PG/PC interface. Add a project comment specifying the S7ONLINE access point and the CPU's MPI/PN address. Engineers changing workstations will not have to re-derive the interface assignment.
• Schedule periodic reorganizations. Run Save As → With reorganization (slow) at major project milestones (e.g. FAT, SAT) to clear internal inconsistencies before they manifest as disabled download controls.

Cross-Reference: Affected Software Versions

The symptom has been observed on the following STEP 7 distributions. The fix is identical across all versions.

For projects migrated to TIA Portal, the project type model does not apply. Download controls in TIA Portal V16 or later are governed by the device configuration and the online/offline consistency check.

Troubleshooting Matrix

Field-Engineer Notes

During commissioning, the disabled download button is often misdiagnosed as a hardware fault because the engineer assumes the PC cannot see the CPU. In practice, the project metadata is the more common source, especially on hybrid sites where the same project has been edited by both the STEP 7 and PCS 7 engineering teams. A 30-second check of the project type field eliminates hours of cable swapping and interface reconfiguration.

When the project type field is locked, do not attempt to edit the .s7p file with a text editor. The internal structure is binary and editing it directly will corrupt the project. Use the SIMATIC Manager dialog exclusively.

For PCS 7 V9.0 and later, the project type is enforced by the engineering license and cannot be switched without uninstalling the PCS 7 add-ons. For STEP 7 V5.5, the switch is permitted and is the documented recovery path.

FAQ