20-750-UFB-1 is an Allen-Bradley universal feedback option module for supported PowerFlex 755 drive products. It provides one option-board platform for several rotary and linear feedback technologies used in closed-loop motor and motion applications.

The module supports Hiperface, EnDat, SSI, BiSS-C and 5 V incremental feedback. Its engineering data covers incremental AquadB signals, high-resolution sine/cosine feedback and externally powered linear sensors, allowing the feedback device, supply and cable arrangement to be matched before installation.

Product Identification

Manufacturer	Rockwell Automation
Brand	Allen-Bradley
Catalog Number	20-750-UFB-1
Product Line	PowerFlex 750-Series
Module Type	Universal Feedback Option Module
Supported PowerFlex Products	755; 755TL, 755TR and 755TM; 755TS
Supported Feedback	Hiperface, EnDat, SSI, BiSS-C and 5 V incremental
Lifecycle Status	Active
UPC	884951061699

Incremental AquadB Interface

Input Arrangement	Differential or single-ended; constant current sink operation, approximately 10 mA
Input Voltage Range	3.5 to 7.5 V DC while sourcing 10 mA
Minimum High State	3.5 V DC
Maximum Low State	0.4 V DC
Maximum Cable Length	30 m (100 ft) at 5 V
Maximum Input Frequency	250 kHz

High-Resolution and Linear Feedback

Encoder Supply	EnDat: 5 V at 250 mA; SSI, Hiperface and BiSS-C: 10.5 V at 250 mA; supported linear sensors: external 24 V supply
High-Resolution Signal	1 V peak-to-peak sine/cosine for EnDat, SSI, Hiperface and BiSS-C
Maximum Cable Lengths	EnDat 100 m; SSI 100 m; Hiperface 90 m; BiSS-C 100 m; supported linear sensors 100 m
Position Update Rate	102.4 microseconds for EnDat, SSI, Hiperface and BiSS-C; 0.5, 1.0, 1.5 or 2.0 ms for supported linear sensors
High-Resolution Maximum Input Frequency	163.8 kHz

• Combines several digital, sine/cosine and incremental feedback formats on one PowerFlex option module.
• Provides the universal feedback path required for homing and registration functions with Studio 5000 Logix Designer embedded motion instructions.
• Uses S1, S2 and S3 DIP switches to route feedback to the primary safety channel, secondary safety channel or both when safety channels are used.
• Includes documented TB1 and TB2 terminal assignments for motor feedback, encoder power, shielding and supported registration or linear-sensor connections.
• Supports Hiperface SC device selection through Universal Feedback parameter P6 for feedback channel 0 or P36 for feedback channel 1.

• Closed-loop motor control using Hiperface, EnDat, SSI, BiSS-C or 5 V incremental feedback on a supported PowerFlex 755 platform.
• Embedded-motion installations that require homing or registration functions through the universal feedback board.
• Safe Speed Monitor arrangements using catalog number 20-750-S1 with supported PowerFlex 755, 755T or 755TM products.
• Rotary-feedback installations that need parameterized encoder selection and documented shield, supply and terminal connections.
• Supported Stahl or Temposonics linear-sensor applications using an external 24 V supply and the specified feedback update settings.

• The standard 20-750-UFB-1 catalog number is listed with an Active lifecycle status.
• Universal Feedback firmware version 1.015 is available for this catalog number.
• 20-750-UFB-1-XT is a separate corrosive-gas-protected catalog number; do not substitute it for the standard module without checking the required hardware version.
• Before replacement, record the host drive, installed option port, feedback-device selection, encoder supply, TB1 and TB2 wiring, shield terminations, safety-channel switch positions and module firmware.

What must be checked before connecting an encoder to 20-750-UFB-1?

Confirm the exact feedback protocol, encoder supply requirement, terminal assignment, cable length, shield connection and the drive parameter used to select the feedback device.

How is feedback routed when the 20-750-S1 Safe Speed Monitor is used?

The S1, S2 and S3 switch positions select the primary safety channel, the secondary safety channel or both. The switch arrangement must follow the required safety-channel configuration.

Why is the universal feedback board used for embedded-motion homing or registration?

The standard single and dual incremental encoder option modules do not support those functions with Studio 5000 Logix Designer embedded motion instructions; the universal feedback board is specified for them.

What roles do TB1 and TB2 have on this option module?

TB1 carries the documented encoder-feedback, power, common and shield connections. TB2 is used in the supported registration and linear-sensor connection arrangements shown for the universal feedback module.

How is a Hiperface SC feedback device selected?

Set Universal Feedback parameter P6 for feedback channel 0 or P36 for feedback channel 1 to device selection 2, Hiperface SC.

What configuration should be retained before replacing the module?

Retain the drive option-port assignment, feedback-device parameters, encoder power arrangement, terminal and shield wiring, safety DIP-switch positions and the installed module firmware.