Electron. Contr 6RY1703-0AA00 6RY1 703-0AA00 6RY17O3-OAAOO

Siemens 6RY1703-0AA00 | SIMOREG DC-MASTER 6RA70 CUD1 Electronic Control Board — C98043-A7001-L1

Part Number: 6RY1703-0AA00

Internal Component Designation: C98043-A7001-L1

Manufacturer: Siemens AG (Germany)

Product Type: CUD1 — Closed-Loop Control Board (Electronic Control / Micro Board) 

Overview

The 6RY1703-0AA00 is the market order number for the CUD1 (Control Unit Digital 1) board — the main digital control board at the heart of every Siemens SIMOREG DC-MASTER 6RA70 DC drive. The internal component label designation C98043-A7001-L1 identifies this as the L1 series version of the CUD1.

The CUD1 is the SIMOREG 6RA70's brain. Two microprocessors on this board execute all of the drive's closed-loop control functions: the armature current regulation loop, the speed control loop, the field weakening characteristic, the ramp function generator, and the protective monitoring algorithms. The board also holds the drive's complete parameter set, handles the DriveMonitor serial interface for commissioning, and manages any fieldbus communication via the option boards plugged into its expansion slots.

The 6RA70 platform divides its electronics into three main boards: the CUD1 (this board — control), the PIB/C98043-A7002 (power interface — thyristor firing), and the FSB/C98043-A7004 (field supply). The CUD1 is the only board that stores drive parameters. When a CUD1 is replaced, the drive's parameter set must be re-entered from a documented backup — the other two boards hold no configuration data.

The L1 designation identifies the earliest CUD1 design generation. Drives with C98043-A7001-L1 are identified as Production State A1 or A2. These drives accept software versions 1.xx and 2.xx only. Later drives (Production State A3 and above) use the L2 board and run software versions 3.xx and above. This hardware/software compatibility relationship must be respected — loading incorrect software versions corrupts the CUD1.

Key Specifications

Parameter Storage and Drive Commissioning

The CUD1 stores the complete parameter set that defines the drive's behaviour: motor data, closed-loop regulator gains, ramp times, I/O configuration, setpoint sources, and protection thresholds. All of this configuration data resides on the CUD1 — not on any other board in the drive.

When replacing a CUD1, the parameter backup is essential. Without a documented backup, the drive requires full recommissioning: motor data re-entry, regulator auto-tuning, I/O reconfiguration, and verification of all protection settings. In a production environment, this can mean extended downtime.

DriveMonitor — Siemens' PC-based commissioning tool for the 6RA70 — can download the full parameter set to a PC file. Any site with SIMOREG 6RA70 drives should have a current DriveMonitor parameter backup for each drive as standard maintenance practice, regardless of whether a board failure is anticipated.

L1 vs L2 Board Compatibility

The C98043-A7001-L1 (6RY1703-0AA00) serves Production State A1 and A2 drives. These drives are identifiable from the rating plate. When sourcing a replacement, confirming that the replacement board's L-series matches the installed drive's production state is mandatory.

Installing an L2 board in an L1/A1-A2 drive (or vice versa) produces an incompatible hardware-software combination that prevents the drive from operating. The mismatch will be evident at power-up — the drive will not initialise correctly.

FAQ

Q1: The SIMOREG 6RA70 shows F063 (RAM fault) or F064 (ROM fault) at every power-up, preventing any operation. Is the CUD1 (6RY1703-0AA00) the likely cause?

F063 and F064 at power-up indicate a memory fault on the CUD1's internal RAM or ROM components — these components are on the CUD1 board itself. A confirmed memory fault means the CUD1 has failed and must be replaced. Before ordering, confirm the production state from the drive's rating plate to ensure the replacement is the L1 series.

Q2: The 6RY1703-0AA00 was discontinued in 2007. Is it still available?

The specialist industrial DC drive aftermarket holds tested CUD1 boards from this series. Exchange programmes — where the faulty board is returned for credit toward a tested unit — are common with DC drive repair specialists. Confirm the L-series on any sourced board matches the L1 requirement before purchase.

Q3: The failed CUD1 has no parameter backup. What is the recommissioning procedure?

Full recommissioning is required: motor nameplate data entry (armature resistance, inductance, rated current, speed), regulator auto-tuning (current and speed loop), I/O and setpoint configuration, and protection threshold verification. Siemens' SIMOREG 6RA70 commissioning guide (available via Siemens Industry Support) details the procedure. Allow at least a full day for a drive with no starting parameter set.

Q4: Can a C98043-A7001-L2 board (6RY1703-0AA01) be used if L1 is unavailable?

No — the L2 board is designed for Production State A3 and above drives and requires software versions 3.xx. Installing L2 hardware in an L1/A1-A2 drive with L1-compatible software will produce an incompatible combination. The drive will not function correctly. If an L1 board is unavailable, a hardware and software upgrade path for the entire CUD1 generation (converting to L2 with matching software) may be an option with specialist DC drive support, but it requires careful planning and is not a simple board swap.

Q5: The 6RA70 platform is aging. Is there a modern migration path if the CUD1 cannot be sourced?

The SINAMICS DCM (DC Master) is Siemens' current DC converter platform and the direct successor to the SIMOREG 6RA70. Migration from 6RA70 to SINAMICS DCM retains the existing DC motor — only the converter electronics are replaced. The DCM covers the same power range and uses PROFIBUS/PROFINET rather than the 6RA70's serial/fieldbus architecture. For sites where CUD1 sourcing has become unreliable, a planned migration to SINAMICS DCM is the long-term solution.