Configuring CP5611 with Citect SCADA on S7-300 Profibus

Configuring the Siemens CP5611 with Citect SCADA on an S7-300 Profibus Network

Integrating a legacy SIMATIC S7-300 CPU 313C-2DP into a Citect (now AVEVA) SCADA HMI through a CP5611 PCI communication processor is one of the most common brownfield integration tasks in European process plants. The CP5611 was the original Siemens PROFIBUS/MPI PCI card for PCs; it was superseded by the CP5611 A2 and later by the CP 5603 (USB) and CP 5711 (USB). The integration can fail at three levels: PC-side driver installation, SIMATIC NET configuration, and Citect port/board addressing. This reference consolidates the field-proven procedure to bring the link up reliably.

1. Problem Definition

Classic symptoms reported by integrators using Citect 5.5 / 6.10 with a CP5611 against an S7-300 CPU 313C-2DP:

• Driver load failure: "zip file is corrupted" when unpacking a third-party Siemens S7 Profibus driver.
• Port stays in "Stopped" state in the Citect Device Editor.
• OPC DA server does not enumerate S7 variables when SIMATIC NET is started in the wrong mode.
• BSEND/BRECV timeout on MPI baud rate (19.2 kbps default), no handshake with the PLC.

Root cause in roughly 80% of these cases is a missing or mismatched SIMATIC NET installation (or a Citect I/O Device pointing to the wrong logical board). The remaining 20% is wiring, baud rate, or PLC PROFIBUS address mismatch.

2. System Architecture

Three implementation paths are viable. The choice depends on the Citect version, the available SIMATIC NET version, and whether the Citect licence includes the native S7 MPI/DP driver.

Architecture B (OPC) is the most robust and is what most field integrators converge on once a single CP5611 problem has eaten a commissioning day.

3. Hardware Identification: CP5611 vs CP5611 A2

Two card variants are commonly encountered in the field. They share the same Windows driver package but differ in firmware and maximum bus speed.

Both cards expose a 9-pin D-sub PROFIBUS connector on the bracket. The CP5611 A2 is the only one still receiving firmware updates in SIMATIC NET v8.x. Cards reported with yellow warning triangles in Windows Device Manager are usually missing the s7onlinx service.

4. Software Prerequisites

The CP5611 Windows driver lives in \Windows\System32\s7onlinx.dll after SIMATIC NET installation. If this file is missing, no Citect I/O Device will start, regardless of Citect configuration.

5. Step-by-Step: Architecture A (Native S7 Driver in Citect)

5.1 Install SIMATIC NET PC Software

1. Insert SIMATIC NET V6.x DVD. Run Setup.exe as Administrator.
2. Select Installation Type: User-defined.
3. Tick the following components:
   • Communication Services - includes S7DOS, S7OPCX, SAPI-S7
   • OPC Server (Data Access)
   • SIMATIC NET Driver for CP5611 / CP5611 A2
4. During hardware detection, point the wizard to the CP5611 slot. The card should appear as CP5611-A2 MPI/DP or CP5611 MPI/DP.
5. After install, run Commissioning > Set PC Station from the SIMATIC NET start menu. Assign the CP5611 to Index 1 in the PC Station configuration.

5.2 Configure STEP 7 Hardware (PLC Side)

1. Open STEP 7, open the S7-300 project.
2. In HW Config, double-click the CPU 313C-2DP. On the DP Interface tab, set:
   • Address: 2 (default; must not conflict with any other DP node)
   • Subnet: PROFIBUS(1) at 1.5 Mbps
   • Operating Mode: DP-Master or DP-Slave (set as Master for SCADA pull)
3. Download HW Config to the CPU.
4. Insert the CP5611 as a DP-Slave in the PROFIBUS subnet; the wizard will add a GSD file (SIEM81AF.GSD for CP5611 A2).

5.3 Verify with SIMATIC NET Diagnostics

1. Start SIMATIC NET Commissioning > Diagnostics (scs7pc.exe or PC Internal station editor).
2. Right-click the CP5611 entry and select Operating Mode > PROFIBUS DP Master.
3. From Diagnostics > Bus Nodes, run a network scan. The CPU 313C-2DP must appear with its configured PROFIBUS address (2).
4. If the node does not appear, the physical bus is the problem (terminators, shielding, baud rate).

5.4 Citect Board Definition

Open the Citect Computer Setup Editor (ctedit) and configure the board:

5.5 Citect I/O Device Definition

Compile the Citect project (ctcomp) and restart the Citect kernel. Watch the Kernel.log for the line:

6. Step-by-Step: Architecture B (OPC DA - Recommended)

When the bundled Citect S7 driver fails or the integrator wants to swap SCADA software later, OPC DA provides a clean abstraction.

6.1 SIMATIC NET OPC Server Configuration

1. Launch Station Configuration Editor (sce.exe) and add the CP5611 to Index 1.
2. Save and close; restart the S7DOS and S7OPCX Windows services.
3. Open the OPC Scout V10 (or the version bundled with your SIMATIC NET). Click Connect to OPC.SimaticNET.
4. Add a new group and define an S7 connection:
   • Name: S7_313C
   • Partner: CP5611 - PROFIBUS
   • Remote Address: PROFIBUS node 2 (the CPU)
   • Rack/Slot: 0/2
5. Test by reading an item, e.g. S7:[S7_313C]DB1,W0. A non-zero value or the configured initial value indicates a working stack.

6.2 Citect OPC Client Configuration

1. In Citect Computer Setup, define a new Board of type OPC.
   • Board Name: OPC_S7
   • Adapter: OPC
   • Address: OPC.SimaticNET (the ProgID of the SIMATIC NET OPC server)
2. Create an I/O Device:
   • Protocol: OPC
   • Address: empty
3. Map a Citect tag to an OPC item name using the syntax:
   • Variable Tag > Item: S7:[S7_313C]DB1,W0
4. Recompile and restart.

7. Driver Download Path: Avoiding "zip file is corrupted"

The Citect native S7 driver historically shipped as SIEMENS_2.01.02_RELEASE.zip. If the archive extracts with errors, the file is partially downloaded. Use the official Siemens delivery channels rather than third-party mirrors:

• Siemens Industry Online Support: support.industry.siemens.com (search for the entry ID 60596849 - CP5611 A2 communication processor manual)
• Citect/AVEVA Driver Packs: supplied with the Citect installation media, or via AVEVA Connect & Control download portal under valid licence.

Verify the zip CRC32 after download. For SIEMENS_2.01.02_RELEASE the expected size is 1.4 MB; smaller files are truncated. Re-download over HTTPS and disable any proxy SSL inspection that mangles binary downloads.

8. Baud Rate and Timing Parameters

For a 1.5 Mbps PROFIBUS segment (default for S7-300 DP), the CP5611 internal timing budget is:

For an MPI link (19.2 kbps or 187.5 kbps), increase the Citect I/O Device timeout to at least 5000 ms; the S7-300 CPU takes up to 2 s to respond on a cold MPI bus.

9. Troubleshooting Matrix

10. Verification Procedure

1. Open OPC Scout V10, read a known S7 tag (e.g. DB1.DBD0 from a project-loaded value). The value must update within 1 s.
2. In Citect Cicode, run DevSetInfo() against the I/O Device. The return value should be 0 (no error).
3. Force a bit in STEP 7 (e.g. DB1.DBX0.0); the corresponding Citect tag must reflect the change within the configured poll period.
4. Disable the CP5611 cable mid-run; Citect should log "Comm Error" and resume automatically when the cable is reinserted (no need to restart the Citect kernel).
5. Run a 24-hour soak test. The Citect Kernel.log should contain zero "BSEND failure" or "S7 timeout" entries.

11. Migration Path: From CP5611 to Modern Hardware

For new installations or when the CP5611 fails, the recommended replacement is the CP 5603 (USB) or CP 5711 (USB), which are functionally identical at the SIMATIC NET API level. Configuration steps in this article remain unchanged; only the Windows driver identifier switches from CP5611 MPI/DP to CP 5603 or CP 5711.

If the S7-300 has an Ethernet CP (CP 343-1 Lean or CP 343-1), the CP5611 can be retired entirely. Use Architecture C (TCP/RFC1006) with Citect I/O Device protocol S7TCPIP on port 102. This eliminates one PC hardware failure domain and improves cybersecurity posture (PROFIBUS cables are a frequent tampering vector).

12. Field-Commissioning Checklist

• [ ] CP5611 / CP5611 A2 seated in 5 V PCI slot, no warning in Device Manager
• [ ] SIMATIC NET PC Software installed, S7DOS and S7OPCX services running and set to Automatic
• [ ] Station Configuration Editor contains CP5611 at Index 1, configuration downloaded
• [ ] STEP 7 HW Config: CPU 313C-2DP DP address matches Citect I/O Device
• [ ] PROFIBUS cable shielded, terminated at both ends, shield grounded at one end only
• [ ] OPC Scout V10 reads at least one tag successfully before launching Citect
• [ ] Citect kernel started with -h to enable hex logging for first 24 h
• [ ] Cyber: Windows firewall restricts S7OPCX to localhost only; remote Citect clients connect via Citect's native TCP port 2074/2075, not DCOM

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