Siemens Sbm Encoder Board 6SE7090-0XX84-0FE0 6SE70900XX840FE0 6SE7O9O-OXX84-OFEO 6SE7 090-0XX84-0FE0

6SE7090-0XX84-0FE0 | Siemens SIMOVERT MASTERDRIVES SBM2 Multiturn Encoder Module — Absolute Value Feedback / Vector Control and Motion Control

Absolute Value Encoders — A Different Feedback Architecture

The SBM2 (Sensor Board Multiturn 2) module provides SIMOVERT MASTERDRIVES drives with an interface for absolute value multiturn encoders — a fundamentally different encoder technology from the incremental encoders that the SBP board (6SE7090-0XX84-0FA0) handles.

Incremental encoders generate relative position information — they count pulses from a reference point (the zero marker) and lose their position knowledge if power is removed or if a reference run is not performed after each power-up.

Absolute value encoders output a unique digital code for every shaft position — a multiturn absolute encoder extends this across multiple revolutions by counting the number of complete turns in addition to the within-turn position. The result is a position value that survives power-off intact. When the drive is powered up again, the SBM2 immediately reads the current shaft position without any reference run being needed.

Key Specifications

Applications Requiring Absolute Multiturn Feedback

Vertical axes: Hoists, elevators, and vertical machining centre spindle heads where the load can move under gravity when power is removed — absolute position knowledge prevents unsafe movement on restart.

Multi-axis coordinated motion: Where the positional relationship between multiple axes must be maintained exactly after a power interruption — absolute encoders on each axis eliminate the need for a synchronised reference run across the whole machine.

Winding and unwinding: In tension-controlled web systems where the accumulated turn count of the roll is critical production data — the SBM2's multiturn count preserves this information through power-off cycles.

Application Scenarios

Absolute encoder feedback fault: A SIMOVERT MASTERDRIVES Motion Control drive develops absolute position feedback faults — the drive cannot read the encoder position or generates SBM2-related alarms. After verifying the encoder and cable, the 6SE7090-0XX84-0FE0 SBM2 module is identified. Replacement restores absolute multiturn position feedback.

MASTERDRIVES encoder upgrade: A facility upgrading a MASTERDRIVES drive from incremental encoder to absolute multiturn encoder installs the 6SE7090-0XX84-0FE0 SBM2 module and the appropriate absolute encoder.

FAQ

Q1: What is a multiturn absolute encoder, and how does it differ from a singleturn absolute encoder?

A singleturn absolute encoder provides a unique position code for every angular position within one revolution (e.g., 0° to 360°) — but does not track how many complete revolutions have occurred. A multiturn absolute encoder adds a revolution counter — tracking both the position within the current revolution and the total number of revolutions. This is essential for applications involving long travel (many turns) where the total displacement, not just within-turn position, must be known precisely after power-off.

Q2: Does the SBM2 module work with all brands of absolute multiturn encoders?

The SBM2 module is designed for absolute encoders using the EnDat or SSI (Synchronous Serial Interface) communication protocols — the standard protocols for absolute encoders used with MASTERDRIVES in industrial motion control applications. Encoders using other proprietary protocols require a different interface. Confirm the encoder's output protocol matches the SBM2's supported interface before ordering.

Q3: What alarms indicate a 6SE7090-0XX84-0FE0 SBM2 module fault?

SBM2 module faults produce absolute encoder communication alarms — the drive reports loss of encoder data or invalid position values. These differ from incremental encoder (SBP) faults in that they typically prevent the drive from knowing its position at all, rather than generating speed-dependent errors. If the encoder itself and its cable test correctly but the position reading remains invalid, the SBM2 module is the next diagnostic focus.

Q4: After replacing 6SE7090-0XX84-0FE0, does the drive need re-homing?

This depends on the specific absolute encoder installation and drive configuration. If the replacement SBM2 correctly re-establishes communication with an undisturbed absolute encoder, the drive should recover the correct position without re-homing — this is the primary advantage of absolute encoder systems. If the encoder was also replaced or disturbed, re-establishing the absolute position reference may be necessary according to the applicable MASTERDRIVES commissioning procedure.

Q5: What ESD precautions apply to the SBM2 module?

Handle the 6SE7090-0XX84-0FE0 with a grounded anti-static wrist strap on an ESD-safe surface. Isolate and lock out the drive mains supply and verify the DC bus has discharged before accessing the drive's internal electronics. The SBM2 module contains precision analog and digital encoder signal processing circuits that are sensitive to electrostatic discharge.