Resolving CP5624 Not Reachable with WinLC RTX TIA Portal V13

Resolving CP5624 Not Reachable with WinLC RTX TIA Portal V13

The Siemens CP 5624 (6GK1562-4AA00) is a PCI Express PROFIBUS / Industrial Ethernet communication processor used to attach a PG/PC station to SIMATIC networks. When deployed as the IF1 submodule of WinLC RTX inside the Station Configuration Editor, the card is frequently reported as NOT REACHABLE even though the WinLC controller shows OK and RUN, and TIA Portal V13 SP1 is still able to download the user program. This article dissects the failure modes, lays out the diagnostic tree, and documents the recovery sequence aligned with the official CP 5623 / CP 5624 manual (BA_CP5623-5624_76.pdf) and the S7-1200 G2 communication reference (TIA Portal cloud manual).

1. CP 5624 Hardware and Driver Foundation

The CP 5624 occupies a single PCI Express x1 slot and is identified by Siemens order number 6GK1562-4AA00. It supersedes the legacy CP 5613 / CP 5614 PCI cards and requires a free PCIe slot — older PCI slots are not supported. The card is delivered with a unified driver package SIMATIC NET PC Software, which exposes both a PROFIBUS-DP/MPI master and an Industrial Ethernet (ISO-on-TCP / TCP / UDP) interface depending on the firmware loadout.

Before chasing a software fault, verify that the CP 5624 is enumerated by Windows Device Manager under Network adapters → SIMATIC NET CP 5624. A yellow bang indicates a driver mismatch or a PCI Express link-width problem. The official manual (CP 5623/CP 5624 manual mirror) specifies that the card must be plugged into a powered PCIe slot providing at least 25 W on the +3.3 V auxiliary rail; under-powered slots lead to silent enumeration failures and a missing entry in the Station Configuration Editor.

2. WinLC RTX Architecture in TIA Portal V13

WinLC RTX is the software PLC runtime that executes the S7-1500-compatible user program on a real-time OS extension (IntervalZero RTX or TenAsys INtime). Within the Station Configuration Editor the WinLC RTX instance is treated as a virtual S7-CPU occupying slot 1, while the CP 5624 occupies an additional submodule position referenced as IF1 (interface 1).

Download works through the virtual backplane between TIA Portal and WinLC RTX because TIA Portal talks to WinLC directly via the local RTX shared memory. The CP 5624 only matters for external PG/PC routing, HMI traffic, or S7-communication to remote stations. This is why a "RUN/OK" WinLC plus a "NOT REACHABLE" CP is a classic symptom: the CPU is healthy, the gateway is the broken link.

3. Root Cause Analysis

From the field reports and from cross-referencing the official Siemens documentation, the unreachable CP5624 falls into one of the following categories:

1. CP 5624 not enumerated in Station Configuration Editor. The driver service SIMATIC NET Communication Service is not started, or the card is recognized by Windows but not registered with the SIMATIC NET configuration daemon. Without that registration, WinLC RTX cannot bind IF1 to a real device.
2. Subnet mismatch between PG/PC Ethernet adapter and WinLC RTX CPU IP. TIA Portal can still reach the CPU because WinLC publishes a virtual Ethernet adapter on a 192.168.x.x range, but the real CP 5624 port sits on a different subnet. The S7-1200 G2 reference (TIA Portal S7-1200 manual) explicitly states that an incorrect subnet mask renders the CPU unreachable for routing through the CP.
3. IE General placeholder used in place of IE interface. The configuration wizard inserts IE General as a generic PROFINET interface when the actual CP 5624 module is not yet dragged from the catalog. IE General works for download but cannot route to physical partners.
4. PCI Express slot issues. Chipset power management (ASPM L1) or riser-card placement disables the card after sleep states.
5. Driver/TIA Portal version drift. TIA Portal V13 SP1 ships SIMATIC NET V13 SP1; running the V14 or V15 driver against the V13 portal causes the configuration editor to refuse to publish the CP slot.
6. Firewall on Windows blocking ISO-on-TCP port 102 and S7-DIRECTORY port. Even with correct IPs, Windows Defender blocks the routing handshake.

4. Pre-flight Checklist

• Confirm Windows recognizes the card: Device Manager → Network adapters → SIMATIC NET CP 5624, no warning icon.
• Confirm driver parity: SIMATIC NET PC Software edition must match TIA Portal major version (V13 SP1 ↔ SIMATIC NET V13 SP1).
• Confirm the SIMATIC NET Communication Service and S7DOS Help Service are set to Automatic and currently Running.
• Capture the Station Configuration Editor diagnostic log: Start → SIMATIC → Station Configuration Editor → Diagnostics → Save Log.
• Verify that WinLC RTX is bound to RTX or INtime; mixed 32/64-bit runtimes will not see the CP.

5. Diagnostic Procedure

1. Open Station Configuration Editor as Administrator. Look for the CP 5624 under Modules → PROFIBUS / Industrial Ethernet. If absent, the driver layer is the problem — re-install SIMATIC NET PC Software matching the TIA Portal version exactly.
2. Check the IF1 binding: right-click WinLC RTX → Properties → Submodules. The IF1 entry must show the CP 5624 with a green tick. A yellow triangle means the binding exists but the physical CP is offline (PCIe power, driver, or firmware).
3. Inspect the CP 5624 IP/subnet: right-click the CP module → Properties → Industrial Ethernet. Write down the IPv4 address and subnet mask. Compare with the PG/PC Ethernet adapter IP via cmd → ipconfig.
4. Ping the CP IP from the PG/PC: ping <CP-IP>. A timeout = routing layer problem (firewall, subnet, cable, switch VLAN).
5. Run the CP diagnostic in TIA Portal: Online → Accessible Nodes. The CP 5624 IP should appear alongside the WinLC RTX CPU IP.
6. Open the Station Configuration Editor log: confirm whether the diagnostic reports CP 5624 not reachable, module not found, or driver version mismatch.

6. Step-by-Step Solution

6.1 Re-install or repair the SIMATIC NET driver

1. Stop SIMATIC NET Communication Service and S7DOS Help Service.
2. Run Setup.exe of SIMATIC NET PC Software V13 SP1 (or matching) as Administrator.
3. Select Repair to enforce driver re-registration of the CP 5624.
4. Reboot. Verify the card is back in Device Manager without warning.

6.2 Bind the CP 5624 in Station Configuration Editor

1. Launch Station Configuration Editor.
2. Click Add → Module → CP 5624. If the catalog is empty, the driver is not registered; return to step 6.1.
3. Drag the CP into the WinLC RTX slot IF1.
4. Assign the Industrial Ethernet IPv4 address (for example 192.168.0.10, mask 255.255.255.0) so that it sits in the same subnet as the WinLC RTX virtual CPU and the PG/PC.
5. Save and close. Confirm no warnings appear.

6.3 Align the subnet mask

The TIA Portal S7-1200 G2 manual (CPU unreachable) is explicit: an incorrect subnet mask isolates the CPU from external clients. Apply this same rule to WinLC RTX:

If any of these three addresses has a mismatched subnet mask, TIA Portal will report the device as not reachable even though the underlying physical layer is healthy. Fix with Properties → Ethernet Address → Subnet Mask.

6.4 Replace IE General with IE interface

The TIA Portal configuration wizard inserts IE General when the CP module is unknown. Delete that placeholder and insert the IE interface submodule of the CP 5624 from the hardware catalog so the WinLC RTX CPU uses a real, configurable PROFINET stack instead of an abstraction.

6.5 Disable Windows firewall for the SIMATIC NET ports

• Open Windows Defender Firewall with Advanced Security.
• Create inbound rules allowing TCP/UDP 102, 34962, 34963, 34964 for the SIMATIC NET profiles.
• Alternatively, toggle the firewall off temporarily for verification, then re-enable with the rules.

6.6 Power management

Open Device Manager → SIMATIC NET CP 5624 → Properties → Power Management. Uncheck Allow the computer to turn off this device to save power. PCIe ASPM L1 must be disabled in BIOS for the CP 5624 as recommended in the CP 5623/CP 5624 manual (CP manual mirror).

7. Verification

1. In TIA Portal V13 SP1 select Online → Accessible Nodes. The CP 5624 IP and the WinLC RTX CPU IP must both appear.
2. Open the project, right-click the WinLC RTX device → Go Online. Status must change from NOT REACHABLE to ONLINE.
3. From the PG/PC command line, run ping -t <CP-IP>; a steady reply confirms the routing layer.
4. Use Online → Online & Diagnostics → Diagnostics on the CP 5624. The diagnostic buffer should be free of Module not found or Submodule mismatch entries.
5. Run S7Diag.exe from the SIMATIC NET installation to scan the bus; the CP 5624 must be listed as an active PROFIBUS master with its MPI/DP address.

8. Firmware and Driver Compatibility Matrix

9. Fault-code Mapping

10. Edge Cases and Field Notes

• VM-hosted WinAC. If WinLC RTX runs inside a virtual machine, the CP 5624 must be passed through (PCIe passthrough) or mapped via SR-IOV. Bridged virtual NICs will NOT expose the CP as an S7 target.
• Hyper-V / VMware Workstation. The Station Configuration Editor under a VM only enumerates virtual NICs. The CP 5624 will be missing because the real card is owned by the hypervisor. Move to bare-metal or use PCIe passthrough.
• Multiple CP 5624 cards. When more than one card is installed, the indexing in Station Configuration Editor follows PCI bus enumeration. Re-seat the cards if the wrong physical port answers.
• Replacement upgrade path. The CP 5624 replaces older CP 5613 A2 / CP 5614 A2 cards only when a free PCI Express slot exists; this is the explicit note in the CP 5623/CP 5624 manual (BA_CP5623-5624_76.pdf).
• Project portability. If the TIA Portal project is migrated to a newer portal version, re-insert the CP 5624 from the catalog — the IF1 binding is not always preserved across version jumps.
• Watchdog timeouts. When the CP 5624 loses its link partner repeatedly, the WinLC RTX may report CPU stop with cause Communication error on IF1. Resolve the link before restarting the CPU to avoid corrupting the diagnostic buffer.

11. Quick Recovery Script (Windows CMD)

:: Reset SIMATIC NET services and CP 5624 binding
net stop "SIMATIC NET Communication Service"
net stop "S7DOS Help Service"
net start "SIMATIC NET Communication Service"
net start "S7DOS Help Service"

:: Refresh PCIe device
powershell -Command "Get-PnpDevice | Where-Object { $_.InstanceId -like 'PCI\\VEN_8086*' } | Disable-PnpDevice -Confirm:$false; Start-Sleep -Seconds 2; Get-PnpDevice | Where-Object { $_.InstanceId -like 'PCI\\VEN_8086*' } | Enable-PnpDevice -Confirm:$false"

:: Verify reachable
ping -n 4 192.168.0.10

12. FAQ