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| Place of Origin | Germany |
| Brand Name | SIEMENS |
| Certification | CE RoHS |
| Model Number | 6SE7090-0XX84-0FF5 |
The Siemens 6SE7090-0XX84-0FF5 is the CBP2 — the PROFIBUS communications board for SIMOVERT MASTERDRIVES Motion Control drive units.
In the MASTERDRIVES modular electronics architecture, a drive unit's control board (the CUMC) handles the motor control algorithms, and option boards installed in the additional slots extend the unit's connectivity and functionality.
The CBP2 is the option board that adds PROFIBUS DP slave capability — allowing the MASTERDRIVES MC drive to participate in a PROFIBUS DP network as a controlled device, receiving speed or torque setpoints from the PROFIBUS master and returning actual values and status information over the same bus.
Without the CBP2 (or a predecessor CBP1), a MASTERDRIVES MC unit communicates with its controller through the USS serial protocol on the CUMC's built-in RS485 interface — an adequate solution for point-to-point control where one or a few drives connect to a dedicated PLC serial port. PROFIBUS DP changes the architecture entirely: multiple MASTERDRIVES drives, along with digital and analog I/O modules, HMI panels, and other field devices, connect to a single two-wire PROFIBUS DP cable that the controller — a Siemens S7-300, S7-400, or CNC system — scans at a deterministic cycle time.
For a production machine with four or eight servo drives, PROFIBUS DP reduces the inter-cabinet wiring from individual serial cables to a single daisy-chained network.
The CBP2 designation (version 2) distinguishes this board from the original CBP (CB1) communications board.
The CBP2 provides improved PROFIBUS performance and additional features compared to the CBP, including enhanced cyclic data transmission and better integration with the MASTERDRIVES MC's motion control features over the PROFIBUS interface.
| Parameter | Value |
|---|---|
| Communication | PROFIBUS DP slave |
| Product Designation | CBP2 |
| Compatible Drives | MASTERDRIVES MC compact + chassis |
| Weight | ~50g |
| Documentation | Not included (available separately) |
| Discontinued | 30 September 2020 |
| Status | Spare part / surplus |
In a MASTERDRIVES installation with CBP2 boards, the drive system integrates into the plant's PROFIBUS DP network as a collection of slaves managed by a PROFIBUS master — typically a Siemens S7-300 or S7-400 CPU with a PROFIBUS DP interface, or a SINUMERIK CNC controller acting as a DP master.
Each MASTERDRIVES drive unit with a CBP2 occupies one PROFIBUS DP slave address on the network.
The PROFIBUS master sends cyclic data to each drive — a control word (enabling or disabling the drive, requesting ramp-up, triggering fault resets) and a speed setpoint as a proportional value.
Simultaneously, each drive returns a status word (drive ready, running, at setpoint, fault active) and an actual value (measured speed as a proportional value).
This cyclic exchange happens automatically at the configured PROFIBUS bus cycle time — typically 1–10ms — without any ladder logic in the PLC to manage the data transfer.
Beyond cyclic data, the CBP2 supports acyclic data exchange — PROFIBUS DP extended functions that allow the PLC or a configuration tool to read and write individual MASTERDRIVES parameters over the PROFIBUS network.
An engineer can upload the drive's parameter set for backup, modify operating parameters (acceleration ramp times, maximum speed limits, control mode), or read diagnostic variables while the drive is operating — all over the existing PROFIBUS cable without disconnecting from the control network.
Within the MASTERDRIVES MC electronics box, the option boards install into specific slots defined by their board type.
Communications boards like the CBP2 install in the designated communications board slot — separate from the slots used for technology boards and encoder boards. The slot position is fixed by the drive unit's internal architecture, and the CBP2's edge connector mates with the corresponding backplane connector in that slot.
The PROFIBUS DP interface itself is a 9-pin Sub-D connector that appears on the front face of the MASTERDRIVES drive unit when the CBP2 is installed — accessible from the front of the cabinet without opening the electronics box.
The PROFIBUS cable terminates at this connector, typically with a PROFIBUS bus connector (6GK1-500 series or equivalent) that provides the bus termination switches and daisy-chain pass-through connections for the next drive on the network.
The PROFIBUS DP address of the CBP2 is set in the MASTERDRIVES parameter set — the CBP2 does not have a physical address switch.
This means the address is stored in the CUMC's non-volatile memory and can be changed through the programming interface without physical access to the CBP2 board itself.
The 6SE7090-0XX84-0FF5 was discontinued on 30 September 2020 as part of Siemens's end-of-life process for the SIMOVERT MASTERDRIVES platform.
Siemens's own spare parts supply continues for a defined support period post-discontinuation, but availability progressively decreases as stock is depleted.
The CBP2 is one of the more commonly needed MASTERDRIVES spare parts because its failure — whether from component aging, electrostatic discharge during incorrect handling, or backplane voltage transients — isolates the affected drive from the plant's PROFIBUS network.
A drive without its CBP2 loses all PROFIBUS communication: the control system cannot send setpoints or read actual values from that axis, and the machine must stop until the board is replaced.
Maintaining at least one CBP2 spare per drive installation — or one per machine — is standard practice for operations that cannot tolerate MASTERDRIVES-related downtime.
Q1: What is the difference between the CBP2 (6SE7090-0XX84-0FF5) and the earlier CB1/CBP (6SE7090-0XX84-0AK0)?
The CBP (Communications Board PROFIBUS, also known as CB1) was the original PROFIBUS DP option board for MASTERDRIVES.
The CBP2 is the improved second generation, offering enhanced cyclic data performance and support for additional PROFIBUS DP features including acyclic data exchange (DP/V1), improved diagnostic functions, and better integration with MASTERDRIVES MC's motion control features over the bus.
Both boards install in the communications board slot, but they are not pin-compatible — the CBP2 cannot directly replace a CBP1/CB1 without verifying the drive firmware version and parameter set compatibility.
Q2: Can the CBP2 be used in SIMOVERT MASTERDRIVES VC (Vector Control) units, or only MC (Motion Control) units?
The 6SE7090-0XX84-0FF5 is specified for SIMOVERT MASTERDRIVES Motion Control (MC) units.
The MASTERDRIVES VC platform uses a different PROFIBUS communications board — the CB1 (6SE7090-0XX84-0AK0) — designed for the VC electronics architecture.
The two platforms have different control boards (CUVC for VC, CUMC for MC) and different electronics box layouts, which makes the MC-specific CBP2 physically and electrically incompatible with VC units.
When ordering a PROFIBUS board for a MASTERDRIVES unit, confirm whether the drive is VC or MC before specifying the board part number.
Q3: Does the CBP2 installation require any parameter changes in the MASTERDRIVES drive unit?
Yes. After installing the CBP2, the MASTERDRIVES drive unit must be parameterised to activate PROFIBUS communication.
The key parameters define the PROFIBUS process data (PKW and PZD words) — which drive variables are mapped to the cyclic setpoint and actual value words, the PROFIBUS slave address, and the baud rate detection setting.
The PROFIBUS baud rate is detected automatically by the CBP2, but the data mapping and slave address must be configured. The MASTERDRIVES drive manual describes the CBP2 parameter structure in detail.
Without correct parameterisation, the drive will not respond correctly to the PROFIBUS master's process data even with the CBP2 physically installed.
Q4: What PROFIBUS baud rates does the CBP2 support?
The CBP2 automatically detects the PROFIBUS bus baud rate — it does not require manual baud rate configuration.
It supports the full range of standard PROFIBUS DP baud rates from 9.6 kbaud to 12 Mbit/s. In practice, most MASTERDRIVES installations use 1.5 Mbit/s or 12 Mbit/s, which provides adequate speed for the drive's cyclic data exchange and leaves capacity for other slaves on the bus.
Q5: Is the CBP2 repairable, or should a failed board always be replaced?
Component-level repair of the CBP2 is technically possible for specialist Siemens drive repair centres equipped with the appropriate test infrastructure.
Common failure modes — capacitor aging, PROFIBUS interface IC failure, power supply regulator failure — can often be addressed at component level, restoring the board to operation at a fraction of replacement cost.
For operations maintaining a large fleet of MASTERDRIVES MC drives, partnering with a Siemens-certified repair service for CBP2 refurbishment is worth considering.
For individual spare needs, new-old-stock CBP2 boards from the industrial surplus market are the practical primary option following the OEM's discontinuation.
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