CUD1 Board C98043-A7001-L2 6RY1703-0AA01 C98043A7001L2 6RY17030AA01 C98O43-A7OO1-L2 6RY17O3-OAAO1 6RY1 703-0AA01

Siemens C98043-A7001-L2 | SIMOREG DC-MASTER 6RA70 CUD1 Electronic Control Board — L2 Series

Part Number: C98043-A7001-L2

Market Order Number: 6RY1703-0AA01

Manufacturer: Siemens AG (Germany / Romania)

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

The Drive's Control Brain — L2 Generation

The C98043-A7001-L2 is the CUD1 (Control Unit Digital 1) board for SIMOREG DC-MASTER 6RA70 DC drives at Production State A3. As the drive's main digital processor, it runs all closed-loop control: armature current regulation, speed control, field weakening, ramp function generation, and protective monitoring. It also stores the entire drive parameter set and manages all fieldbus communications via the option module slots.

The L2 designation identifies the second-generation CUD1 hardware. It applies exclusively to Production State A3 drives and accepts only software versions 3.xx. Earlier Production States A1 and A2 use the L1 board (C98043-A7001-L1, market no. 6RY1703-0AA00), which runs software v1.xx and v2.xx. Fitting L2 hardware to an L1/A1-A2 drive, or loading v1.xx/v2.xx software onto an L2 board, produces an incompatible combination — the drive will not initialise correctly.

L2 vs L1 — Generation Differences

The L2 CUD1 introduces capability improvements over L1. Software version 3.xx brings expanded parameter functionality, enhanced communication options, and refined closed-loop control algorithms. The L2 board also supports a wider range of option boards through the LBA (Local Bus Adapter) slot — including PROFIBUS communication boards (CBP), technology boards (T400), and other expansion modules.

Always verify the drive's production state from its rating plate before ordering a replacement CUD1. Production state is typically identified in the drive's order number suffix or internal documentation.

Parameter Backup Is Non-Negotiable

The CUD1 holds all drive parameters. There is no other location in the 6RA70 where parameter data is stored. Before replacing the C98043-A7001-L2, a full parameter backup via DriveMonitor is essential. Without a backup, the drive requires complete recommissioning — motor data, regulator tuning, I/O assignments, and protection settings must all be re-entered from scratch.

Key Specifications

FAQ

Q1: The 6RA70 shows F063 (RAM fault) or F064 (ROM fault) at power-up on every attempt. Is the CUD1 the cause?

Yes. F063 and F064 at power-up indicate an internal memory fault on the CUD1 board itself — the RAM or ROM components have failed. These faults cannot be cleared by reset or parameter adjustment. The C98043-A7001-L2 must be replaced.

Q2: Can the L1 board (C98043-A7001-L1) replace the L2 in a Production State A3 drive?

No. L1 and L2 are hardware-incompatible for Production State A3 drives. An A3 drive requires the L2 board with v3.xx software. Fitting an L1 board produces a mismatch that prevents the drive from initialising. Always match the board generation to the drive's production state.

Q3: There is no parameter backup. What is the recommissioning procedure after CUD1 replacement?

Collect all available documentation: MTB commissioning sheets, the SIMOREG 6RA70 parameter manual, and any maintenance notes. Enter motor nameplate data first, then run regulator auto-optimisation for current and speed loops, and reconfigure all I/O and setpoint assignments. Plan for at least a full working day on a drive with no baseline parameters.

Q4: The CUD1 was replaced but the drive now shows communication errors on the PROFIBUS connection. The bus was working before. What changed?

The PROFIBUS address and communication parameters are stored on the CUD1. After fitting a replacement board, these parameters revert to defaults. Re-enter the correct PROFIBUS node address (P927) and verify all communication parameters match the original configuration before attempting bus communication.

Q5: Is the C98043-A7001-L2 available new, or only as an aftermarket part?

With the SIMOREG 6RA70 platform at end-of-life, new units from Siemens are subject to availability. The industrial DC drive aftermarket — specialist repair companies and legacy spare parts dealers — is the most accessible source. Request a functional test certificate and confirm the L2 designation on the board label before accepting delivery.