CPU 317-2PN/DP Migration and SINAMICS G120 Profinet Integration

CPU 317-2PN/DP Migration and SINAMICS G120 Profinet Integration

Engineering reference for two parallel workstreams: (a) replacing an S7-300 CPU 315 with a CPU 317-2PN/DP while preserving the existing Profibus DP trunk, and (b) commissioning two SINAMICS G120 drives on the new integrated Profinet IO controller. The flow is written for STEP 7 V5.5 and V5.6 (HW Config) and applies to projects originally built on V5.5 that are now being upgraded on a V5.6 engineering station for offline migration work.

1. Migration Context and Topology Decision

The CPU 315 family (6ES7315-2AG10-0AB0, 6ES7315-2EH13-0AB0, 6ES7315-2FJ14-0AB0) provides one combined MPI/DP port and no integrated Profinet IO controller. Adding Profinet-capable drives such as SINAMICS G120 with a CU240E-2 PN Control Unit to the same station therefore requires either an external CP 343-1 or a CPU that carries an integrated PN IO controller. The CPU 317-2PN/DP family (6ES7317-2EK14-0AB0 with firmware V3.3 and 1 MB work memory, or 6ES7317-2AJ10-0AB0 with firmware V2.7 and 512 KB) provides both a Profinet IO controller with a 2-port managed switch and a Profibus DP master on a single device. This is the most compact migration path because the existing Profibus DP trunk and its DP slaves stay connected to the DP port without any hardware rearrangement.

The substitution is mechanical and electrical: the CPU 315 and the CPU 317-2PN/DP share the S7-300 backplane footprint and the slot-2 mounting position. The 24 V DC supply, the MPI connector (now used for PG routing only), and the DP connector all remain in the same physical positions. The only physical port added is the RJ45 Profinet interface pair on the lower front of the CPU 317-2PN/DP.

2. Prerequisites

• STEP 7 V5.6 SP1 or higher installed on the engineering station. STEP 7 V5.5 on the plant PG is sufficient for runtime editing as long as the offline project file is round-tripped through the V5.6 station when the GSDML updates are required. STEP 7 V5.7 is also valid; the dialogs are identical.
• SINAMICS G120 GSDML package matching the Control Unit firmware. For a CU240E-2 PN used in this project, install GSDML-V2.31-Siemens-SINAMICS_G120_CU240EPN-<releasedate>.xml or higher (V2.35 is current at time of writing). The package is delivered as a ZIP from the Siemens Product Support entry ID 109748529 ("SINAMICS G120 GSD/GSDML").
• A PG/PC Ethernet interface reachable to the CPU 317-2PN/DP Profinet port for online diagnostics, device-name assignment, and program download.
• The S7 project with the existing CPU 315 configuration, symbol table, and S7 connections intact.
• For each new Profinet slave, an Ethernet cable (Cat 5e minimum, Cat 6 recommended for industrial cabinet environments) terminated to RJ45 with TIA-568B pinout, and a managed switch or direct-coupling to the CPU 2-port switch. Star topology is the simplest; linear topology is supported only when the slaves carry an integrated 2-port switch (SINAMICS G120 with CU240E-2 PN does carry one).
• STARTER V5.4 SP1 or higher, or Startdrive V15.1 or higher (TIA Portal), to commission the SINAMICS G120 parameter sets and verify the telegram selection against the HW Config slot.

3. Decoding the SINAMICS G120 MLFBs

SINAMICS G120 is a modular drive. The 12-digit MLFB identifies the Power Module and the integrated Control Unit together because the G120 is shipped as a single assembled unit when the suffix encodes the CU. The two drives in this project are:

Decoding rule for the suffix -XYZ<n>:

• The 11th character identifies the Control Unit family: A = CU240B-2 (basic), U = CU240E-2 (enhanced), S = CU250S-2 (servoless).
• The 12th character identifies the fieldbus: B = Profibus DP, F = Profinet, P = RS485 only (USS / Modbus RTU).
• The trailing digit encodes functional scope (safety, encoder, etc.).

Conclusion for this project: the 6SL3210-1KE23-2UB1 is a CU240E-2 DP drive, which is reachable on Profibus DP, not Profinet. To attach it to the new PN IO controller, either replace the Control Unit with a CU240E-2 PN (field swap of the CU on top of the Power Module is supported by the G120 design) or accept that this drive remains on the existing DP trunk via an ET200S PN/DP coupler. The 6SL3210-1KE26-0UF1 is a CU240E-2 PN drive and connects directly to the Profinet subnet of the CPU 317-2PN/DP.

4. CPU 317-2PN/DP Variants and Compatibility

Use the 2EK14 variant if the application includes drives requiring IRT (isochronous) mode. For the standard Telegram 1 / Telegram 20 closed-loop speed control flow described here, either variant is sufficient, but the larger work memory of the 2EK14 allows the additional DBs required for the G120 drive parameter shadow to fit without spilling into the load memory. STEP 7 V5.6 SP1 ships an HSP (Hardware Support Package) that adds the 2EK14 to the catalog under SIMATIC 300 → CPU → CPU 317-2PN/DP → 6ES7317-2EK14-0AB0. If the HSP is missing, install it from Options → Install HW Updates.

5. Profinet Topology Planning

The CPU 317-2PN/DP exposes two RJ45 Profinet ports labelled PN1 (Port 1) and PN2 (Port 2). They belong to the same internal managed switch and form one Profinet IO system with the CPU acting as the IO controller. Two topology patterns are valid:

1. Star with external managed switch (recommended): PN1 connects to a managed switch (SCALANCE XB-000 or similar). All Profinet slaves, including the CU240E-2 PN drive, the IM 151-3 PN HF head stations, and any future HMI panels, drop off individual ports of the switch. Diagnostics is simplified because every slave has a dedicated port.
2. Linear (daisy chain): PN1 connects to the first slave; the second port of that slave connects to the next. The CU240E-2 PN carries a 2-port switch, so it can act as a linear coupler. This reduces cabling but loses the slave if any link in the chain fails and complicates PRP/HSR redundancy paths.

For this project, use the star topology. The IM 151-3 PN HF stations and the CU240E-2 PN drive drop off individual ports. The Profibus DP trunk remains attached to the CPU DP port with its original DP slaves.

6. Step-by-Step: Replacing the CPU in HW Config

1. Open the project in STEP 7 V5.6 SP1.
2. Open HW Config. Locate the CPU 315 in slot 2.
3. Right-click the CPU 315 → Replace Object → navigate to SIMATIC 300 → CPU → CPU 317-2PN/DP → 6ES7317-2EK14-0AB0.
4. Confirm the replacement. HW Config will retain all configured S7 connections, the symbol table, and the existing Profibus DP slave configuration attached to the DP port.
5. Open the CPU properties dialog. Under the Profinet Interface tab, enter the desired IP address, subnet mask, and router address. For a private plant network the typical scheme is 192.168.1.10 for the CPU, mask 255.255.255.0.
6. Under the Profinet IO tab, leave the IO controller role enabled (default).
7. Under Time-of-Day Synchronization, enable Synchronize via Profinet if a synchronization master is in the plant (for example, an HMI or SCALANCE acting as NTP forwarder). Otherwise disable to avoid unsynchronized NTP retries flooding the diagnostic buffer.
8. Click OK and return to HW Config. Save and Compile (Ctrl+S, then Station → Consistency Check).

7. Installing the SINAMICS G120 GSDML in STEP 7 V5.x

1. Download the latest GSDML ZIP for the SINAMICS G120 family from Siemens Product Support entry 109748529.
2. Extract the ZIP to a known path, for example C:\Siemens\GSD\SINAMICS_G120\. The extracted folder contains the GSDML-V2.31-Siemens-SINAMICS_G120_CU240EPN-<date>.xml plus a bm_catalog directory with bitmap icons.
3. In STEP 7, open HW Config and choose Options → Install GSD File.
4. Browse to the extracted folder, select the .xml file, and confirm.
5. STEP 7 will parse the GSDML, register the device types under PROFINET IO → Drives → SINAMICS → SINAMICS G120 CU240E-2 PN, and copy the bitmaps into the catalog tree.
6. Close and reopen HW Config if the catalog tree does not refresh immediately.

After installation, the catalog exposes the following slots for a CU240E-2 PN:

8. Adding the IM 151-3 PN HF to the Profinet IO System

1. Open HW Config. Drag the CPU 317-2PN/DP PN interface into a Profinet IO System.
2. From the catalog, navigate to PROFINET IO → I/O → ET200S → IM 151-3 PN HF (6ES7151-3BA23-0AB0). Drag the head module onto the Profinet IO system line.
3. Assign an IP address (e.g., 192.168.1.20) and a Profinet device name (e.g., et200s-pn-01) in the properties dialog.
4. Populate the slots under the IM 151-3 PN HF with the power module, digital input/output modules, and any analog modules from the existing project. The slot order matters: Power Module (PM-E or PM-DC) goes in slot 1, then I/O modules from slot 2 upward.
5. Save and Compile.

9. Adding the SINAMICS G120 PN Drive to the Profinet IO System

1. From the catalog, navigate to PROFINET IO → Drives → SINAMICS → SINAMICS G120 CU240E-2 PN. Drag the device onto the Profinet IO system.
2. Assign an IP address (e.g., 192.168.1.30) and a Profinet device name (e.g., g120-pn-01) in the properties dialog.
3. Click into the slot 1 configuration of the drive. Select the desired telegram from the drop-down. For closed-loop speed control with a single setpoint, choose Standard Telegram 1 (4 words input + 4 words output: STW1/ZSW1/NSOLL_A/NIST_A). For applications requiring torque setpoint and ramp-function generator control, choose Standard Telegram 2.
4. If a higher-level control requires acyclic parameter access (e.g., reading r0021 actual speed in a higher resolution than NIST_A provides), add the PKW channel by inserting it into slot 1 alongside the cyclic telegram.
5. Save and Compile.

10. Telegram and I/O Mapping Reference

The I/O addresses appear in the slot properties. For Telegram 1 on a CU240E-2 PN at slot 1, the standard mapping is input word address IW 256 (ZSW1) and IW 258 (NIST_A), output word address QW 256 (STW1) and QW 258 (NSOLL_A). The exact address offset depends on the slot number within the Profinet IO system; verify with HW Config → PLC → Module Information or by reading the offline address list.

11. Device Name and IP Address Assignment

Profinet IO uses a device name (string) as the primary identifier for the controller to address the slave during cyclic data exchange. The IP address is then assigned by the controller during the AR (Application Relationship) establishment phase using the LLDP neighborhood discovery. The procedure to assign a device name to a fresh slave:

1. Connect the PG to the Profinet subnet (directly to the CPU PN port or via the same managed switch).
2. Open PLC → Ethernet → Edit Ethernet Node in STEP 7. Click Browse to list reachable devices.
3. Select the SINAMICS G120 entry (identified by MAC address label on the front of the CU). Assign the configured device name (e.g., g120-pn-01) and the configured IP address. Click Assign IP Configuration.
4. Repeat for the IM 151-3 PN HF stations and any other PN slaves added to the project.

12. Program Migration Considerations

The CPU 317-2PN/DP firmware V3.3 expands the OB, FB, and DB counts compared to a CPU 315. Existing code compiled for the CPU 315 will recompile without change on the CPU 317-2PN/DP, but the following points deserve attention:

• OB1 cycle time: CPU 317-2PN/DP at V3.3 supports up to 300 OB priorities. Default OB1 is fine; ensure OB82 (diagnostic interrupt), OB83 (module removal), OB86 (rack failure), OB121 (programming error), and OB122 (I/O access error) are present, particularly for the new Profinet IO system.
• Process image partitions (PIPs): Telegram data from the CU240E-2 PN can be tied to a PIP (e.g., PIP 1) and updated synchronously via OB 61-64. This is required if isochronous mode is enabled.
• SFB/SFC compatibility: All SFB0-SFB255 and SFC0-SFC255 that compiled on CPU 315 are supported. Watch for SFB52 (RDREC) and SFB53 (WRREC), which are used for acyclic record access on Profinet slaves. These read/write the G120 parameter set over the standard PKW channel via index 0xB02E (PROFIdrive parameter channel).
• Consistent data blocks: When reading NIST_A (actual speed) as a 32-bit value, declare the relevant DB area with STRUCT aligned on a word boundary and use DPRD/DATD instructions (SFC14 / SFC15) to guarantee consistent data transfer. Direct PQW/PER load is only safe for non-time-critical data.

13. Compile, Save, and Consistency Check

1. In HW Config, click Station → Consistency Check. Resolve any reported duplicate addresses or unconnected slaves.
2. Click Save and Compile. HW Config regenerates the system data blocks (SDB 1000 and higher) and writes them into the offline project.
3. Open the block container and ensure all blocks compile cleanly: right-click Blocks → Compile All.
4. Download the entire station (Blocks + System Data) to the CPU 317-2PN/DP. The CPU will go through a restart (warm restart with the default startup OB100).
5. After restart, verify the CPU is in RUN by observing the RUN LED and the diagnostic buffer entry "Restart (warm) executed".

14. Commissioning the SINAMICS G120 with STARTER

1. Open STARTER and connect to the CPU 317-2PN/DP via Profinet. Navigate to the SINAMICS G120 PN node in the project tree.
2. Run the Commissioning Wizard. Enter the motor nameplate data (rated voltage, current, power, cos phi, speed, frequency).
3. Execute the motor identification routine (p1910 = 1 for rotating measurement, p1900 = 1 for static). The drive accelerates the motor briefly; ensure the mechanical system is safe for this rotation.
4. Verify the telegram in STARTER matches the HW Config telegram. Mismatch will raise F01910 (setpoint timeout) or A08502 (PROFIBUS/PROFINET setpoint fault).
5. Save the parameter set to the CU's non-volatile memory (RAM to ROM copy).

15. Verification Checklist

16. Diagnostic LEDs and Error Codes

Common SINAMICS G120 fault codes encountered during PN commissioning:

17. Troubleshooting Matrix

18. Frequently Asked Questions