Resolving CP5512 Driver Installation Error on STEP 7 V5.3

1. Problem Description

When commissioning a SIMATIC PC Station against an S7-314 CPU (6ES7314-xxx-xx-xx) over MPI, an engineer configured the CP 5512 (Siemens order code 6GK1551-2AA00) PCMCIA card together with the MPI programming cable c79459-a1890-a10 (HW adapter for CP 5511/CP 5512). The PC Station was inserted in the STEP 7 project, the Station Configurator Editor matched the indexed components, and NetPro > Save and Compile returned no diagnostics. Despite a clean compile, STEP 7 V5.3 raised the dialog:

"Could not install a driver"

The error appeared the moment the engineer selected PLC > Download or Online > Accessible Nodes. The block transfer aborted before the S7-314 was reached, leaving the CPU untouched. The same error appears whether the user invokes Download, Upload Station to PG, or Online > Monitor/Modify.

Environment:

• STEP 7 V5.3 (S7-Station programming tool, build >= V5.3 + SP3 typical)
• SIMATIC Net 2005 Edition (PC Station software, version 2005 + HF)
• PC with PCMCIA slot (CardBus or earlier), CP 5512 inserted
• MPI cable c79459-a1890-a10 between CP 5512 and S7-314 MPI port
• S7-314 (any 6ES7314-... variant) with default MPI address 2, baud 187.5 kbps

Symptoms that typically co-present with this dialog:

• NetPro diagnostics free of errors
• Station Configurator shows the CP 5512 index entry as "Configuration mode"
• Windows Device Manager lists the CP 5512 as operational (no yellow bang)
• STEP 7 Set PG/PC Interface still has the CP 5512 (MPI) selected as Online Access

2. Root Cause Analysis

The root cause is a mode/interface mismatch between the role the CP 5512 is playing in the PC Station configuration and the role STEP 7 expects when it acts as a programming device rather than a configurator.

CP 5512 has two mutually exclusive operating modes that the Station Configurator Editor controls:

When the PC Station is compiled, the Station Configurator binds the CP 5512 to Configuration mode. STEP 7 V5.3 then cannot simultaneously bind the same physical card to its PG/PC interface stack, and the loading of the S7PCI / S7Mpi driver fails, surfacing as "Could not install a driver".

Secondary causes that surface the same dialog:

1. Wrong online interface selected in Set PG/PC Interface. The CP 5512 (MPI) entry is highlighted, but the card is already owned by the SIMATIC Net stack in configuration mode.
2. SIMATIC Net service not started. The SIMATIC Net Configuration Service must be running before STEP 7 attempts the bind.
3. Conflicting driver ownership. The CP 5512 driver (s7pciXXX.sys family) is bound to the SIMATIC Net stack; the STEP 7 programming interface stack (s7wnci??.dll / S7Mpi driver) is denied a handle.
4. MPI address collision with the PC Station's logical address slot.
5. CardBus / PCMCIA power management suspending the CP 5512 between Station Configurator and STEP 7.

3. Affected Versions, Hardware and Order Codes

The "Could not install a driver" dialog is associated with the Windows kernel driver family s7pciXX.sys (CP 5512) and acpibXX.sys (older CP 5511). When the bind to a STEP 7 user-mode handle fails, STEP 7 raises the message before the actual MPI/Profibus transaction starts.

4. Pre-Diagnostic Procedure

Before changing settings, capture the following baseline so the change can be reversed if a new symptom emerges.

1. Open Start > SIMATIC > SIMATIC Net > Station Configurator and screenshot the component list. Note which CP 5512 index entry exists (component index 1 is typical).
2. Open Start > SIMATIC > STEP 7 > Set PG/PC Interface and record the currently selected access point of STEP 7 (typically S7ONLINE).
3. Open Windows Device Manager and verify the CP 5512 shows no warning. Record driver file version and provider (Siemens AG).
4. In STEP 7, open Options > PC Interface (when SIMATIC Net is installed) and confirm the active assignment table.
5. Open Control Panel > Administrative Tools > Services. Confirm SIMATIC Net Configuration Service is Started and Startup Type = Automatic.

5. Solution A — Switch the Online Interface to PC Internal

This is the resolution that proved effective in the field. The PC Station is kept as a SIMATIC Net configuration target, while STEP 7 is rerouted through the loopback interface for online access to the S7-314.

1. In STEP 7, choose Options > Set PG/PC Interface.
2. Select the access point S7ONLINE.
3. In the interface list, choose PC Internal (local) instead of CP 5512 (MPI).
4. Click OK. The interface assignment is stored in %WINDIR%\system32\s7onlinx.xml and the registry key HKLM\SOFTWARE\Siemens\STEP7\Online.
5. Confirm in PLC > Accessible Nodes that the S7-314 (MPI = 2) appears.

The PC Internal interface does not require any physical hardware; it talks to the SIMATIC Net stack on the same host. If the PC Station is compiled and the CP 5512 is in configuration mode, the SIMATIC Net stack carries the MPI traffic from the PC Internal endpoint out through the CP 5512 to the S7-314.

6. Solution B — Switch the CP 5512 to Programming Mode

Use this path only when the PC Station is not needed (i.e., STEP 7 alone is the engineering client) or when a second CP 5512 is available to dedicate to STEP 7.

1. Open Station Configurator Editor.
2. Locate the CP 5512 component. Right-click and select Mode > Programming mode.
3. Stop and restart the SIMATIC Net Configuration Service so the change is registered.
4. Restart STEP 7.
5. Open Options > Set PG/PC Interface. The entry CP 5512 (MPI) is now bindable. Select it as the access point of STEP 7.
6. Click Diagnostics and run Test; the S7-314 should be detected at MPI address 2.

7. Station Configurator and NetPro Validation

When the PC Station is the engineering target, the binding between components must be consistent. Validate as follows.

1. In NetPro, open the PC Station; the CP 5512 index should map to slot index 1 (or as configured in the Station Configurator). The Index tab of the component must show the same number as the Station Configurator entry.
2. Save and compile. No error should appear in the Compile/Diagnose window.
3. Open the Station Configurator; the CP 5512 row must show Mode = Configuration and a green status indicator (component active, configuration downloaded).
4. Open Start > SIMATIC Net > Commissioning Wizard and run a Diagnostics pass. The wizard reads the running configuration of the PC Station; any mismatch between Station Configurator and the live stack is flagged here.
5. Confirm in SIMATIC Net > PC Station > Diagnostics that the CP 5512 line shows OK and the S7 connection status is Established for any configured S7 connection.

8. Verification Procedure

1. From STEP 7 V5.3, select PLC > Accessible Nodes. The S7-314 (MPI address 2) must appear in the list with status Online.
2. Open the S7-314 hardware object in HW Config. Verify the rack configuration matches the physical plant.
3. Initiate PLC > Download. The "Could not install a driver" dialog must not appear. A standard download progress dialog replaces it.
4. After successful download, open an OB1 instance and toggle a tag in the watch table. The change should be visible in the S7-314 within one cycle (OB1 cycle, typically 50-200 ms for a small 314 program).
5. Run PLC > Monitor/Modify on a few I/O addresses to confirm live data flow.

9. MPI Cable and Hardware Setup

The CP 5512 connects to the S7-314 MPI port through the dedicated MPI HW adapter. Verify the physical layer first.

The c79459-a1890-a10 adapter integrates the bus terminator (220 Ω between pins 3 and 8, plus 390 Ω pull-up on pin 3 and pull-down on pin 8) on the S7-314 side. Do not add a second terminator. Default MPI baud is 187.5 kbps. Both ends of the bus must be terminated; for a 2-node point-to-point link the CP 5512 side is terminated by the adapter, and the S7-314 MPI port has its own internal terminator that is enabled when the bus is the final segment.

When using c79459-a1890-a10 / 6ES7901-0BF00-0AA0, the cable is pre-assembled and pre-terminated. Maximum segment length is 50 m at 187.5 kbps. For longer runs, switch to Profibus with 1.5 Mbps (CP 5512 supports up to 12 Mbps).

10. Fault and Symptom Matrix

11. Extended Field Notes

11.1 Driver Ownership

The CP 5512 is a single PCMCIA resource. Only one stack can own the device at a time. SIMATIC Net and STEP 7 each load their own version of the CP 5512 kernel driver. On Windows XP/2003, the driver family is s7pciXX.sys and s7wnciXX.dll. The Service Control Manager assigns the device to whichever user-mode process binds it first. The SIMATIC Net service binds it on boot; STEP 7 cannot subsequently claim it for online use unless the user manually disables the SIMATIC Net service. The recommended architecture is therefore to keep the SIMATIC Net service in control and to bind STEP 7 through the PC Internal interface (Solution A).

11.2 SAPI Buffer and Cycle Time

When using PC Internal + SIMATIC Net, the round-trip latency between STEP 7 and the S7-314 is dominated by the SAPI (SIMATIC Application Programming Interface) call into the SIMATIC Net stack. Typical latency on Windows XP with the 2005 edition is 8-30 ms per transaction, depending on PC load. For OB1 cycle times shorter than the latency, do not assume each cycle reflects the previous download; use monitoring with handshake.

11.3 Migration Path to Modern Stack

The CP 5512 is end-of-life. For new projects, use a CP 1623 (6GK1162-3AA00) PCIe, or a USB/PPI adapter for temporary commissioning, or a CP 5711 (USB to Profibus/MPI). STEP 7 V5.3 and SIMATIC Net 2005 are also legacy; current installations should be evaluated for migration to STEP 7 V5.6 or TIA Portal V16+. The diagnostics, Station Configurator logic, and PC Internal + SIMATIC Net pattern, however, remain conceptually identical.

11.4 Safety and Commissioning Constraints

12. FAQ