Sinamics G130 CU320 DCC Parameters Not Found After Drive

Problem Overview

A SINAMICS G130 chassis unit with a CU320 Control Unit is integrated into a PROFIBUS DP network with a SIMATIC S7-400 as the class-1 master. Three identical G130 drives run the same application. One unit fails, is replaced with a new factory-built drive, and parameter download is executed from a known-good peer. After the download the new drive accepts ON commands from the local AOP30 operator panel but the drive ignores start/stop commands and references issued from the DCS / PLC over PROFIBUS. In the online parameter list the following entries return Does not exist:

• p21000 – Run-time group properties, Run-time group 1
• p21601 – Profibus_Active
• p21602 – Remote_CMD_Active
• p21603 – HW_Switch_local
• p21604 – Spare_Cmd_Sel
• p21701 – Start_Push_button
• p21702 – Start_Input2
• p21703 – Start_Input3
• p21704 – Start_Input4
• p21801 – Running
• p21802 – Fault_Reset_Loc
• p21805 – Flt_Reset_NoRun
• p21806 – CDS_Change
• p21807 – Stop_PushButton_Local
• p21808 – Stop_Spare
• p21901 – Start_Cmd
• p21902 – Stop_Cmd
• p22001 – CDS_Status

The same indexes render correctly on the original running drive. From a parameter-backup standpoint everything looks correct; from a control standpoint the drive is dead to the master.

Root Cause Analysis

The p21000, p2160x, p2170x, p2180x, p2190x, and p22001 parameters shown in this failure are not standard SINAMICS parameter numbers. They are user-defined connect parameters generated by a Drive Control Chart (DCC) project that the original engineering team compiled and downloaded to the original CU320.

The parameter ranges used here map onto the DCC free-parameter blocks of the SINAMICS parameter tree:

The standard parameter upload/download feature of STARTER only transfers the drive parameter image (p0000 through about p3999 plus technology-relevant firmware parameters). It does not transfer DCC charts, DCC source code, or the user-defined parameter objects the chart generates. A factory-fresh CU320 therefore ships without any of the p21500-p22001 entries — even though the parameter backup file looks complete.

Sinamics G130 / CU320 Architecture Recap

The G130 is the chassis-style low-voltage drive family built around the CU320 Control Unit. Two CU320 variants exist:

• CU320 (single-axis, used in G130 line-ups)
• CU320-2 (multi-axis, used in S120)

Both share the same parameter model and the same DCC runtime, but their project files differ. The DCC runtime itself is firmware-resident and license-protected (license key on the CF card / CU320 memory). The chart executable is downloaded by STARTER and held in volatile memory until Copy RAM to ROM is performed, or until the project is downloaded with the Store additional data on the target device option enabled.

For PROFIBUS communication the G130 uses the CBE20 (or PROFIBUS CBE20-expansion slot) communication board. Key parameters for PROFIBUS on a G130:

The DCC chart in this application forms an OR/AND gate over the local hardware inputs and the PROFIBUS control word, then exposes a clean Start_Cmd / Stop_Cmd pair on r21705.0 / r21809.0 that the rest of the drive is wired to. Without the chart the drive is functionally disconnected from its control logic.

Diagnostic Procedure

Confirm the diagnosis before spending time loading charts. Perform the checks in order.

1. Parameter inspection in STARTER (online → drive). Open the parameter list and filter by index range 21000-22001. All entries must return Does not exist on the new drive but must return real values on the old drive. If true, the chart is absent.
2. Drive object view: under the project tree expand Control_Unit > Drive_Unit_1 > Drive_1. If the offline project lists DCC charts but the online view shows none, the chart executable was never downloaded.
3. Version check: read r0018 (firmware version). Compare with r0296 (firmware file version stored in NV). Identical means the CU320 image is clean.
4. CFG file comparison: in STARTER select Target device > Read out device configuration. Cross-reference the configured axis and DCC option entries with the original.
5. License check: in Commissioning > Licenses confirm that the DCC license key is present on the CU320. A new factory drive may arrive without the DCC license even if hardware supports it.
6. PROFIBUS wiring: LED status on the CBE20 must show solid green for RUN and flashing/green for data exchange when the master is online. If the LED pattern is wrong, the issue is not DCC — it is cable, address, or GSD mismatch.
7. PROFIBUS address: in this case the old drive sat at node 47 (per p918 on the good drive) but the new drive is at 45 after parameter download. The S7-400 master is talking to node 47. Realign p918 to 47 on the new drive and power-cycle the PROFIBUS interface.

Solution Path A — Restore the Original DCC Project

This is the preferred path because it gives a 1:1 replica of the original drive including all parameter numbers, BICO links, and chart tuning.

1. Locate the original STARTER project file (.zap or .zip). It must contain the DCC chart source. If the engineering department does not have it, request it from the original programmer or from the Siemens Industry Online Support for archived customer projects.
2. Open the project in STARTER V5.x with the DCC option installed and a valid DCC editor license. Verify chart sources by opening the chart — if the editor refuses to open the chart the license is missing or the source was stripped.
3. Right-click the drive → Load to target device. In the load dialog the critical selection is Store additional data on the target device and Include DCC chart data. Both must be active.
4. Confirm the download. After completion the parameter list must now resolve p21000, p21601-p21604, p21701-p21704, p21801-p21808, p21901-p21902, p22001 to real values.
5. Save to non-volatile memory: Copy RAM to ROM, or re-download with the Save permanently option.
6. Power-cycle the CU320 to verify the chart survives a warm restart.

Solution Path B — Upload Existing Chart From a Working Drive

If a peer drive is still running, the chart executable can be uploaded to the offline project and then downloaded to the new drive. This path requires that the original download was performed with the Store additional data on the target device flag set.

1. Connect STARTER to a known-good G130 in the same fleet.
2. Right-click the online drive → Upload to PG/PC. The chart sources will land in the offline project only if Additional data on target device was previously enabled.
3. Compare the uploaded DCC library with the offline project. Verify chart version, instance, and parameter number ranges.
4. Disconnect, connect to the new drive, and download the project back through STARTER with both Include DCC chart data and Store additional data on target device ticked.
5. Perform Copy RAM to ROM.

Solution Path C — p21500 Workaround (Project Source Unavailable)

If the original STARTER project and chart source are permanently lost, you can still recover basic PROFIBUS control by abandoning the custom chart logic and routing start/stop directly through a standard SINAMICS parameter set. The reduced fallback uses p21500 as a generic technology/DCC flag parameter and falls back to the drive's native command source.

1. Set p085 = 0 and p115 = 0 temporarily to release the active command source.
2. Set p081 = 0 (no source, command from native PROFIBUS channel).
3. Set the command source selection p922 to PROFIBUS (control word 1 over r2090.0).
4. Map p1075 = r2093.0 if needed for direct setpoint bit.
5. Configure p2100 / p2101 for fault acknowledgement over PROFIBUS (control word bit 7 via r2093.7).
6. Verify local AOP30 start still works while the chart stubs are absent.
7. Cycle the drive and verify the S7-400 master exchanges cyclic PZD: parameter r2047 (cyclic state) reads Operating.

PROFIBUS Integration Verification

After the chart is loaded the loop must be closed through the S7-400. The drive expects:

• Word 1 received (control word 1) at r2090[0] with bit 0 (ON/OFF1), bit 1 (OFF2), bit 2 (OFF3), bit 3 (enable operation), bit 7 (fault acknowledge) driven by the PLC logic.
• Word 2 received (setpoint) at r2090[1] carrying the speed setpoint in INT16 normalised to p2000 / INT32 in the configured telegram scaling.
• Word 1 sent (status word 1) at r2089[0] reporting bit 0 (ready to switch on), bit 1 (ready), bit 2 (running), bit 3 (fault), bit 6 (switching on inhibited), bit 10 (control requested).
• Word 2 sent (actual speed) at r2089[1] scaled to p2000.

The default telegram for a free combination on G130 is SIEMENS telegram 1 (2/2 PZD). Confirm with the project; if the original used a custom PCS7 telegram, the S7-400 HW-config in the STEP7 project will not exchange data without that exact selection.

For acceptance, run this verification sequence on the bench or in commissioning mode:

1. Energise the drive, leave PWM blocked by p085 = 0 + missing ON command.
2. Force r2090[0] = 047Eh (control word: 0110_0111_1110b — ON, no OFF2/OFF3, enable, ramp generator enable, setpoint enable, fault ack).
3. Set r2090[1] = 16384 (50% reference speed via INT16 = 4000h).
4. Pulse r2090[0] = 047Eh rising edge followed by 047Fh to issue pulse enable.
5. Observe r2089[0] drives from 0000h through the closing sequence to FB07h (Operation); the DCC chart's r21705.0 = 1 and r899.1 (running) = 1 follows.

Preventive Measures for Future Replacements

Checklist Before Returning the Drive to Production

1. All DCC parameters visible (21000-22001 range at minimum)
2. p918 matches the field address (47 in this site)
3. DCC chart view shows the same blocks and instances on the new drive as on the others
4. Local AOP30 ON/OFF matches the DCS ON/OFF
5. Step response via r2090[1] setpoint change produces expected ramp on r0063
6. Copy RAM to ROM performed; survive a CU320 power-cycle
7. Fault buffer clear (r0949 = 0 list, r2133 = 0 buffer)
8. S7-400 cyclic PZD reports OK and no diagnostic interrupt at the PROFIBUS master
9. DCC license valid on Commissioning > Licenses page

FAQ