Bei924-01017-022ARotary Incremental Optical Encoder, 625 PPR, A/B/Z Single-Ended, 7406R Open-Collector Output with Internal Pull-Ups, LED Source, Shaft Seal

Product Description

What this part is

This is a BEI Sensors H29-series rotary incremental optical encoder. A shaft-driven optical disc generates two square-wave channels 90° apart plus a once-per-revolution index pulse, so a controller can count position, work out direction from the channel phasing, and find a repeatable home reference. It is an incremental encoder, not an absolute one and not a resolver: it reports change, so position is known only after homing.

924-01017-022A is BEI’s factory model number for this build. H29E-SB-625-ABZ-7406R-LED-S is the same encoder written as its configuration string, with every field readable.

Decoding the model string

H29: the H29 heavy-duty industrial encoder family. The number reflects the housing size class.

E: the housing and mounting configuration within the family.

SB: the shaft configuration and diameter code.

625: 625 pulses per revolution. A controller scaled for one PPR reads every other one as a wrong feed rate or a wrong position.

ABZ: output channels, A and B in quadrature plus the Z index, single-ended. ABZC in the BEI scheme adds the complementary channels for differential transmission. A drive or counter card expecting differential A/Ā, B/B̄, Z/Z̄ is not served by this build.

7406R: the output driver, 7406 open collector with internal pull-up resistors. BEI sizes those pull-ups at roughly 100 ohms per volt of supply and the driver’s current sink is limited, making this a modest-drive output rather than a differential line driver.

LED: LED light source rather than an incandescent lamp. The lamp is the wear item on older optical encoders, and an LED build is the long-life option.

S: shaft seal fitted.

Output type and pulse count

The output type is the compatibility gate rather than the pulse count. Open collector with internal pull-ups suits a short, clean cabinet run into a counter or PLC high-speed input, and it tolerates a receiver whose logic supply differs from the encoder’s. Without the common-mode rejection of a differential pair, a 30 m run alongside a motor cable picks up PWM noise and produces phantom counts, which present as position drift that grows over a shift rather than as an obvious fault. A long run or a noisy environment calls for a differential (ABZC) line-driver build.

625 PPR is an unusual, deliberately chosen count. Counts like 625 exist because the machine’s gearing or lead makes the arithmetic come out in round engineering units, often a metric lead or a specific gear ratio, so a 500 or 1000 PPR encoder is not a neutral swap even where it fits the shaft. The Z index fires once per turn, and its position relative to the machine’s home switch sets repeatable homing.

The shaft seal suits a machine environment with coolant mist or swarf around the mounting face, which is why it is specified on an industrial H29 rather than a laboratory unit.

Published specifications

Type: rotary incremental optical encoder, shaft driven.

Resolution: 625 pulses per revolution.

Output channels: A, B in quadrature, plus Z index, single-ended.

Output driver: 7406 open collector with internal pull-ups, approximately 100 ohms per volt, limited current sink.

Light source: LED.

Shaft seal: fitted.

BEI factory model number: 924-01017-022A.

Quantity and configuration

Sold as one encoder. No mating cable or connector, no flexible shaft coupling, no mounting flange, adapter plate or tether arm, and no manual are included.

Interchange guidance

Searched as 924-01017-022A, 92401017022A, 924 01017 022A, 924-01017, H29E-SB-625-ABZ-7406R-LED-S, H29E-SB-625-ABZ-7406R-LED, H29ESB625ABZ7406RLEDS and BEI H29 625 PPR encoder. Related builds in the same family that differ in one field only: an H29E-SB-625-ABZC-7406R-LED-S adds the complementary channels for differential output, and other PPR counts (500, 1000, 1024, 2048) share the identical housing and shaft. All are carried as cross-references because they capture the same search, at a different output type or pulse count. BEI’s related H25 and HS25 families use the same configuration-string scheme and the same 7406R and ABZ/ABZC output options, so H25 datasheets are the practical reference for decoding an H29 order code. Brand history for search reach: BEI, BEI Sensors, BEI Ideacod, BEI Duncan and now Sensata Technologies, which supports the H-series range today.