CP 5613 PROFIBUS Commissioning First-Time S7 PLC Download

Overview

Commissioning a fresh Siemens SIMATIC S7-300/400 network that mixes CPUs and PC stations equipped with CP 5613 (catalog 6GK1 561-3AA00 / A2) PROFIBUS cards requires a specific download sequence. The most common commissioning failure on a greenfield network is the chicken-and-egg problem created by the combined MPI/DP interface on the CPU: once the CPU's hardware configuration is loaded with PROFIBUS-DP enabled, the port stops responding to native MPI download requests. This article provides the field-proven procedure for first-time download on a network of two S7 CPUs and three PC stations with OPC servers, using STEP 7 V5.5 and SIMATIC NCM PC.

Network Architecture

Reference topology for the procedure described in this article. The same logic scales to additional CPUs and PC stations.

Hardware Requirements and CP 5613 Specifications

The CP 5613 (and the more recent CP 5613 A2 and CP 5623) is a PCI / PCIe master card for PROFIBUS and MPI. It is the recommended PG/PC interface for STEP 7 V5.5 and SIMATIC NCM PC installations.

Verify in the SIMATIC Manager PG/PC Interface dialog (Start → SIMATIC → STEP 7 → Set PG/PC Interface) that the CP 5613 driver is installed and visible. The two access points relevant to this procedure are:

• S7ONLINE (STEP 7) — used by SIMATIC Manager to download to the CPU.
• CP_L2_1 — default CP 5613 access point used by NCM PC and the Station Configurator.

PROFIBUS Cabling and Termination

Terminators on a PROFIBUS-DP segment must be powered: the 220 Ω pull-up and 390 Ω pull-down resistor network only forms the correct DC bias when the terminating node (CP 5613 or CPU) is energized. An unpowered terminator behaves as a stub impedance and degrades the signal, especially at 1.5 Mbit/s and above.

PG/PC Interface Selection: CP 5613 MPI vs PC Internal

STEP 7 distinguishes between two interface modes for the CP 5613. The choice controls the first-time download strategy.

The first time you load a fresh CPU, the MPI/DP port is still in MPI mode (factory default). Therefore:

1. Set S7ONLINE = CP 5613 MPI in Set PG/PC Interface.
2. Open HW Config, assign the CPU's PROFIBUS interface to address 2 (CPU 1) or 3 (CPU 2), set the mode to DP master or DP slave as the project requires.
3. Download the hardware configuration. The CPU reboots and the port is now DP.
4. Switch S7ONLINE to PC Internal (or to CP 5613 PROFIBUS if you want to go through the bus) for the PC station download.

Bus Parameter Profile Selection

Open Set PG/PC Interface → PROFIBUS Interface CP 5613 → Properties → PROFIBUS. The Bus profile field selects which timing parameters the CP 5613 broadcasts during PG/PC access.

For the network in this article, select Standard until all stations are online. After commissioning, run the PROFIBUS diagnostics (Start → SIMATIC → STEP 7 → Commissioning → Bus Diagnostics) to verify zero Faults/1000 messages. If the rate is non-zero, switch to DP / FMS Universal or to user-defined timing.

Prerequisites

1. STEP 7 V5.5 (or later SP) installed on every PC station that needs to download a project.
2. SIMATIC NCM PC for PROFIBUS installed and licensed (NCM-PC V5.5+).
3. CP 5613 driver installed on each PC station. The driver is part of the SIMATIC NET CD and is registered under Start → SIMATIC → SIMATIC NET → Commissioning PC Station.
4. The STEP 7 project is fully compiled: HW Config → Station → Check Consistency must pass with no errors.
5. PROFIBUS cable is laid, connectors are crimped (Fast Connect stripping tool 6GK1 905-6AA00), and terminating resistors are switched ON at the two end nodes (and OFF at every other node).
6. A unique node address is assigned to every node, in the range 0–126. CPU 1 = 2, CPU 2 = 3, PC 1 = 4, PC 2 = 5, PC 3 = 6 is a workable default.
7. The CPUs are in factory state (MRES performed, or factory reset via mode selector to position MRES for 5 s).

Step-by-Step Commissioning Procedure

The procedure has two distinct phases: Phase A downloads CPU hardware and program via MPI; Phase B distributes the PC station configurations via PC Internal / Station Configurator.

Phase A — Load the CPU Hardware Configuration

1. On PC Station 1, open Set PG/PC Interface and set S7ONLINE to CP 5613 MPI. Confirm the CP 5613 is the assigned interface.
2. Power on CPU 1 only. All other nodes (CPU 2, PC 2, PC 3) are still disconnected from the bus or powered down.
3. Open the project in SIMATIC Manager. Open HW Config on CPU 1.
4. Right-click the MPI/DP interface object → Object Properties → General → Interface → Type: PROFIBUS. Assign address 2, leave transmission speed at 1.5 Mbit/s.
5. From the HW Config menu, select PLC → Download to Module. Acknowledge the "Stop CPU" warning. The CPU enters STOP, the configuration is loaded, and the CPU remains in STOP if the project specifies it.
6. After the download, the port is now DP. Verify with PLC → Accessible Nodes that CPU 1 reports itself at address 2 over PROFIBUS.
7. Power down CPU 1. Move the bus connector from CPU 1 to CPU 2. Power on CPU 2.
8. In HW Config, switch to the CPU 2 view. Repeat steps 4–6 with address 3.
9. Reconnect CPU 1 to the bus. Power on both CPUs.

Phase B — Load the PC Station Configurations

1. On PC Station 1, open Set PG/PC Interface and set S7ONLINE to PC Internal (local).
2. Open the Station Configurator (Start → SIMATIC → SIMATIC NET → Commissioning PC Station → Station Configurator).
3. From the Station Configurator, select Import → Station and choose the project's .xdb file for PC Station 1 (it is in the project's PC Station folder, typically named PC1.xdb).
4. The Station Configurator now lists CP 5613 at PROFIBUS address 4 and the OPC server (or S7 OPC, or WinCC, depending on what is in the project). The status indicator should turn green.
5. From SIMATIC Manager, open the PC Station view and select PLC → Download to PC Station. This pushes the project to the PC's local database (PC Internal) so the OPC server knows which tags to read from which CPU slot.
6. Verify with Start → SIMATIC → SIMATIC NET → Commissioning PC Station → Diagnostics that CP 5613 is Active and the OPC server has reached Running state.
7. Use OPC Scout (Start → SIMATIC → SIMATIC NET → OPC Scout) to add an OPC item, e.g. S7:[CPU1]DB1,W0. The quality flag must show Good.
8. Repeat steps 1–7 on PC Station 2 and PC Station 3, importing the corresponding PC2.xdb and PC3.xdb files. No additional CPU download is required — the project is already complete.

Working with XDB Files

The .xdb file is a serialised snapshot of HW Config for a single PC station. It is produced by SIMATIC Manager → PC Station → Save as XDB and is imported by the Station Configurator on the target machine.

Baud Rate and Cabling Planning

Use the following inequality to size the bus for a given segment length and number of devices. The PROFIBUS-DP standard (IEC 61158 / EN 50170) defines the maximum stub length as a function of baud rate.

L_segment ≤ L_max(baud)
L_stub ≤ L_{stub_max}(baud)

For a commissioning environment where a service laptop will be tapped in and out of the bus through the PG port, stay at or below 1.5 Mbit/s so the stub stays within the 6.6 m budget.

OPC Server Verification

1. Open OPC Scout on the PC station. Create a new group named e.g. Verify_Group.
2. Add an OPC item: S7:[S7 connection_1]DB1,W0. The connection name is the one defined in NetPro → S7 Connections.
3. Right-click the item, Active. The value field populates and the quality becomes Good (0xC0).
4. Force a value from the CPU side (VAT or watch table) and confirm the value updates in OPC Scout within the configured update interval (default 100 ms, configurable per S7 connection in NetPro → Properties → S7 Connection → Special Properties).
5. If the quality remains Bad (0x00), the S7 connection has not been compiled. Re-open NetPro, PLC → Compile and Check All, then re-download to the PC station.

Verification Matrix

Troubleshooting Matrix

Common Field Pitfalls

• Setting the PG/PC interface to the wrong CP 5613 mode. CP 5613 MPI and CP 5613 PROFIBUS are two distinct entries in the device list. The download dialog uses S7ONLINE, but a separate CP 5613 PROFIBUS access is used by NCM PC. Verify both before starting.
• Forgetting to re-power the segment after reconnecting a node. A connector inserted while the bus is live can present a stub impedance that briefly destabilises the segment.
• Using the S7-200 PPI cable instead of a PROFIBUS cable. The PPI cable is MPI-compatible but does not support 1.5 Mbit/s reliably for first-time CPU download.
• Leaving the default MPI address (0) and the project's address (2) in conflict. If the CPU's MRES is not performed, the previous project may still be active and will reject a download from a different source address.
• Importing the wrong XDB. All PC stations in the project have similar filenames; confirm the PC Station → Properties → Name matches the physical PC before importing.

Post-Commissioning Hardening

1. Lock the bus profile in HW Config (Properties → Network → Settings → Do not participate in bus parameter negotiation). This prevents a rogue PG from changing slot times.
2. Document every node's address and a sketch of the cable run in the project's Documentation folder.
3. Take a baseline of bus diagnostics (Statistics → Save) and archive it with the project.
4. Set the OPC server's update interval to the application requirement (typical 100–500 ms for SCADA, 10–50 ms for tight control loops).
5. Schedule a 24 h soak test with the diagnostic counters running; the failure curve (faults/1000 messages vs time) is the best early indicator of connector or cable degradation.

FAQ