SIMOREG 6RA7091 Parameter Setup: Commissioning 1200A DC Drive

1. Overview: SIMOREG 6RA7091-6FV62-0 in Industrial DC Drive Applications

The SIMOREG DC-MASTER 6RA7091-6FV62-0 is a fully digital, three-phase thyristor converter from the Siemens SIMOREG 6RA70 series, designed for armature and field supply of separately excited DC motors up to the megawatt class. With a rated DC armature current of 1200 A and a typical armature voltage range of up to 750 V DC (line-side 3-phase 400-690 V AC), the 6RA7091 is the larger sibling of the 6RA7085 (600 A) and the smaller 6RA7090 (900 A) units, all sharing a common CUD1/CUD2 control card architecture and the same parameter tree.

This reference targets the field commissioning of a 375 kW DC motor controlled by a 6RA7091-6FV62-0, integrated over PROFIBUS-DP to a SIMATIC S7-400 master. It consolidates the canonical minimum-parameter set, X171 binary I/O mapping, PROFIBUS addressing, and recovery from the well-documented F031 fault triggered by a parameter-memory (A7009 EEPROM) board swap.

For the manufacturer hardware manual and the parameter list, refer to the Siemens Industry Online Support portal at support.industry.siemens.com, specifically the SIMOREG DC-MASTER 6RA70 operating instructions (C98130-A1256-A002-*) and the parameter list (C98130-A1256-A003-*). The firmware/software version of the CUD card is reported in r060 (CUD1) and r065 (CUD2).

2. Hardware Identification and Type Plate Data

Before any parameter is changed, the order number (MLFB) on the type plate must match the application. The relevant variants in the SIMOREG 6RA70 family for a 375 kW DC motor are:

The trailing -0 indicates the standard CUD1 (single-channel control unit) configuration. -0Z suffixes denote a second CUD2 fitted in the right-hand slot (option K00). The drive identification is read back digitally in r070: a healthy 6RA7091 reports r070 = 110. The 6RA7085 reports r070 = 108; the 6RA7090 reports r070 = 109. If r070 shows a value that does not match the type plate, the firmware on the parameter memory has been loaded from a different power section - a common symptom after a board exchange (see Section 12).

3. CUD Card, Firmware Version, and Parameter Memory (A7009)

The CUD1 card (left-hand slot) holds the active firmware and the runtime parameter image. The optional CUD2 card (right-hand slot) can act as a redundant controller, a technology board, or a parameter back-up. Both cards carry an EEPROM (designation A7009 on the schematic) that stores the drive's parameter set non-volatilely.

• r060 — CUD1 software version (e.g. 2.5, 3.1, 4.2 depending on release)
• r065 — CUD2 software version (only present if fitted)
• r070 — Power section order number (read-only visualization)
• r071 — Rated armature current of the connected power section (e.g. 1200)
• r072 — Rated armature voltage / supply class

Critical field fact: r070 is a visualization parameter. It is not writable from the keypad or DriveMonitor. It is only refreshed by a parameter download that includes a power-section matching image, or by an explicit "Upload to EEPROM" operation that originates from the correct firmware/parameter set.

4. Parameter Access Levels (P051, P052)

SIMOREG 6RA70 segregates parameters into visibility classes. The two principal access-control indices are:

Procedure to unlock all parameters at first commissioning:

1. Apply control voltage (24 V) to the electronics; main contactor may remain off.
2. On the PMU keypad, navigate to P051 and enter 40. Press P to confirm.
3. Navigate to P052 and enter 3. Press P to confirm.
4. Wait for the change to take effect. The full parameter list (indices 0…999) is now visible.

To restore factory defaults (chapter 7.4 of the operating instructions), set P051 = 21 and acknowledge. This resets every writable parameter in the active function data set. Always perform a factory reset before a clean re-commissioning.

5. Minimum Required Commissioning Parameters (P078, P100…P108)

After unlocking, the minimum-parameter set from chapter 7.5 of the operating instructions is entered. The values come directly from the motor nameplate and the field supply rating.

For a typical 375 kW separately excited DC motor with a 440 V armature and 500 V base, set:

P078.001 = 400
P100 = 1200
P101 = 440
P102 = 15.6   (verify against motor plate)
P104 = 1500
P108 = 1800   (or equal to P104 if no field weakening)

6. Speed Feedback Selection (P083, P741, P082)

Speed feedback options on the 6RA70 are configured by three coordinated parameters:

For an analog DC tacho (e.g. 60 V / 1000 rpm) on a 1500 rpm base-speed motor:

P083 = 1
P741 = 60.0
P082 = 0    (no field weakening if max speed equals base speed)

If the application is a crane hoist with constant-torque below base speed and field weakening above, set P082 = 1 and verify P103 (minimum field) is correctly entered so the drive does not collapse flux at no-load.

7. Ramp Generator and Acceleration / Deceleration (P303, P304)

The internal ramp-function generator is parameterized by:

For a 375 kW hoist drive these must be coordinated with the mechanical brake release/apply times (typically 0.2–0.5 s). If the ramp is too short relative to brake response, the drive will trip on F035 (overcurrent) or F036 (overvoltage) on stop.

8. X171 User Terminal — Binary I/O Mapping

The CUD1 card carries the X171 sub-D connector for the user's binary control signals. The terminal assignment referenced in field practice is:

For forward/reverse through a single PLC output, wire the binary input 0 (pin 36) such that 0 V = forward and 24 V = reverse (or the opposite, depending on plant convention). The polarity is then locked in by the Bico indices P671 and P672 rather than by re-wiring.

9. PROFIBUS-DP Integration with SIMATIC S7-400

PROFIBUS-DP is the standard fieldbus for SIMOREG 6RA70. The relevant parameters are:

Recommended PPO type for crane applications is PPO1 (4 PKW + 2 PZD words) for cyclic setpoint / actual exchange, with the process-data words mapped in HW Config of the S7-400 master. The GSD file is SIEM8115.GSD for the SIMOREG 6RA70 family.

Address conflict avoidance:

1. Verify P918 is unique on the segment. DriveMonitor can write P918 only when no other master is actively communicating with that node.
2. If the segment is shared with a SIMATIC panel, set the panel as a class-2 master and the S7-400 as class-1.
3. Confirm the bus terminator is powered and that A/B wires are not swapped at the X178 PROFIBUS connector on the CUD1 card.

10. DriveMonitor Commissioning Tool

DriveMonitor (Siemens order number 6RX1700-0AD76 for the older releases) is the PC-based parameterization, trace, and optimization tool that communicates with the CUD1 over RS232 (X175 on the front of the CUD) or over PROFIBUS (FDL/DP-V0). For first commissioning:

1. Connect the PC serial port (or USB-to-RS232 adapter) to the CUD1 X175 socket with the Siemens cable (order 6SX7005-0AB00).
2. Set the on-screen COM port to 9600 / 8 / N / 1 (default for CUD1; later firmware supports 19200 and 57600).
3. Press "Online" in DriveMonitor. The active node is read from the CUD1 EEPROM and displayed.
4. Upload the parameter set to the PC (Read → All parameters) before any optimization. This is the snapshot used for offline editing.
5. Use the Trace function to record actual speed, actual current, and EMF during the first manual run.

11. Automatic Optimization Runs (P051 = 25, 26, 27, 28)

After the minimum parameters are entered, the closed-loop regulators must be tuned. SIMOREG 6RA70 supports four optimization routines, started by entering a special key in P051:

Each routine pulses the appropriate controller, records step response, and writes the resulting P/I gains. The optimization takes 10–90 s. The drive displays the running optimization in r047 (operating state).

12. F031 Fault — Cause and Recovery

The F031 fault on a SIMOREG 6RA70 indicates an internal parameter / power-section mismatch: the CUD firmware has detected that the loaded parameter set does not match the connected power section. Typical triggers are:

1. EEPROM A7009 board was replaced (the new memory contains parameters from a different power section, e.g. a 6RA7085 image was loaded into a 6RA7091 chassis).
2. The CUD card was swapped between two drives of different rating.
3. A corrupted parameter download from DriveMonitor produced an inconsistent image.

Recovery procedure (per the operating instructions, chapter 7.10):

1. Power down the drive; wait for the DC bus to discharge (> 5 min for 1200 A unit).
2. Insert the correct firmware card or download the correct parameter file for a 6RA7091-6FV62-0 via DriveMonitor.
3. Reconnect DriveMonitor and verify r070 = 110 for a 6RA7091 (or 108 for 6RA7085, 109 for 6RA7090). Do not attempt to write r070 directly — it is read-only.
4. Perform a factory reset (P051 = 21).
5. Re-enter the minimum parameters (P078, P100…P108, P083, P741, P082, P303, P304).
6. Run the optimization routines 25 → 26 → 27 → 28 in order.
7. Clear the fault buffer (P053 = 0) and acknowledge F031.

Field case from the source: a 6RA7091-6FV62-0 reported r070 = 108 (6RA7085) and raised F031. Root cause: the A7009 EEPROM had been replaced the previous day by a third-party maintenance contractor using a spare board from a 600 A drive. The mismatch between the EEPROM image and the actual 1200 A power section was the fault source. Replacing the EEPROM with one flashed from a known-good 6RA7091 backup, followed by the procedure above, cleared the fault.

13. Two-Drive / Four-Motor Crane Topology (Field Case)

A common SIMOREG deployment is a 2-drive / 4-motor crane where each SIMOREG is wired to two mechanically coupled motors through contactors. Functional data sets (FDS) of the 6RA70 are designed for exactly this:

• FDS 0 — default, single-motor operation
• FDS 1 — parameter set for motor 1 of the pair
• FDS 2— parameter set for motor 2 of the pair
• FDS 3 — parameter set for tandem operation (both motors)

The active FDS is selected by binary inputs (typically terminal 36 and 37). Each FDS carries its own copy of the speed-controller gains, the ramp times, and the current limits, so a contactor changeover does not require re-optimization. Verify that the FDS bits are wired such that a 00↔11 transition does not glitch the regulator enable.

14. Fault Code Reference (F030…F039 family)

From the SIMOREG 6RA70 fault list (chapter 8 of the operating instructions):

15. Step-by-Step Commissioning Checklist (375 kW, S7-400, PROFIBUS)

1. Mechanical installation complete; cabinet bonded; cooling fans tested.
2. Verify line-side 3-phase 400 V AC at the input busbars; measure phase-to-phase voltage with a true-RMS meter.
3. Verify 24 V DC control supply at X9 (electronics power); status LEDs on CUD1 green.
4. PMU keypad: set P051 = 40, P052 = 3.
5. Set P078.001 = 400, P078.002 = 400 (or per plant).
6. Set P100 = 1200, P101 = 440, P102 = 15.6, P104 = 1500, P108 = 1800.
7. Set P083 = 1 (tacho), P741 = 60.0, P082 = 0 (or 1 if field weakening).
8. Set P303 = 3.0, P304 = 3.0, P306 = 0.5.
9. Configure X171: pin 36 = F/R, pin 37 = Run, pin 38 = Enable, pin 39 = Jog.
10. Set P918 = 3 (drive 1 PROFIBUS address) and confirm GSD is loaded in S7-400 HW Config.
11. Run optimization P051 = 25 (armature), 26 (field), 27 (speed), 28 (field weakening).
12. First no-load run from the PMU keypad: setpoint ±5%, verify direction, tacho polarity, current limit.
13. Couple to load, run a slow reference ramp, record first traces in DriveMonitor.
14. Hand over to S7-400 cyclic communication; verify control word bits 0…3 toggle the states reported in r010 (status word).
15. Save a parameter back-up to the PC: File → Save As → *.dnx and to a second EEPROM if available.

16. Troubleshooting Matrix

17. Spares and Replacement Boards

Critical spare cards for a 6RA7091-6FV62-0 fleet:

• A7009 — parameter memory EEPROM (order under MLFB 6RY1703-0AA02 or per Siemens spare-parts list for the cabinet series)
• CUD1 — control unit, left slot (MLFB 6RY1803-0AA0x, where x matches the firmware version)
• CUD2 — optional redundant control unit, right slot
• A7001…A7004 — firing-pulse amplifier cards per phase
• Thyristor modules — paired per phase leg; verify the part number on the heat-sink label

For crane applications, keep one A7009 EEPROM per drive rating (one for 6RA7085, one for 6RA7091) and update the back-up image after every commissioning change.

18. Field-Proven Caveats

• On older 6RA70 firmware (< 2.5), the optimization routines (P051=25..28) may not write to the active FDS; verify the active FDS in r045 before each run.
• The PROFIBUS connector on the CUD1 (X178) is not hot-pluggable. Always power down the bus segment before disconnecting.
• If two SIMOREG nodes share a DriveMonitor session, write operations to P051 = 21 on the wrong node will factory-reset an unrelated drive. Use the DriveMonitor node picker carefully.
• The minimum-parameter set in chapter 7.5 of the manual covers basic 4-quadrant operation. For a 1-quadrant (non-reversing) hoist, additional parameters (P150..P155, current-limit profile) must be reviewed.

19. Reference Documentation

Consult the following Siemens primary documents, available from support.industry.siemens.com:

• SIMOREG DC-MASTER 6RA70 Operating Instructions, order number C98130-A1256-A002-*-7619 (latest edition). Available as PDF: C98130-A1256-A002-14-7619.
• SIMOREG DC-MASTER 6RA70 Parameter List, C98130-A1256-A003-*
• SIMOREG DC-MASTER 6RA70 Functional Description, C98130-A1256-A004-*
• DriveMonitor Commissioning Tool Manual, C98130-A1256-A005-*
• PROFIBUS GSD file SIEM8115.GSD — downloadable from the Siemens Product Support page for 6RA70.