Allen-Bradley 845T-HC12PFW-1 Encoders

Configured for precise shaft position tracking in Allen-Bradley motion control networks, the Allen-Bradley 845T-HC12PFW-1 (845T Optical Encoder) provides direct physical/electrical execution. Operating as a heavy-duty rotary encoder, this unit generates dual-channel incremental quadrature pulses (Channel A and B) to convert mechanical shaft rotation into high-resolution digital feedback for speed and position regulation circuits without active signal degradation.

Hardware Specifications

Deterministic Network Feedback & I/O Line Isolation

The 845T series encoder integrates a 5 VDC differential line driver output to maintain deterministic feedback loops over long cable runs within high-noise industrial environments. Its dual-channel quadrature arrangement (A and B channels) enables precise direction sensing and 1024 PPR position tracking. Shielded output circuits and internal optoelectronic decoupling safeguard signal integrity against EMI noise, preventing frame errors when transmitting positioning data to high-speed PLC input cards or servo drive controllers.

Frequently Asked Questions

Q: What power supply input range is required for operating the 845T-HC12PFW-1 encoder?

A: The encoder operates strictly on a regulated 5 VDC input supply, providing matching 5 VDC Differential Line Driver (DLD) pulse outputs for Channel A and Channel B signal processing.

Q: How is the pigtail cable shield grounded during field wiring?

A: The integrated 1 m (3.28 ft) pigtail cable drain wire and shield braid should be tied directly to a single-point chassis ground at the receiving controller or interface module to prevent ground loops while suppressing common-mode noise.

Field Installation Guidelines

1. Disconnect all electrical power sources driving the system controller and sensor circuit prior to mechanically mounting the encoder.
2. Align the 1/4 inch diameter encoder shaft with the driven motor or machine shaft using a flexible shaft coupling to prevent excessive radial and axial bearing loads.
3. Secure the encoder housing via the servo face mount holes using appropriate mounting hardware, verifying shaft concentricity within specified mechanical tolerances.
4. Route the 1 m pigtail cable in dedicated signal conduits separated from AC power lines or variable frequency drive (VFD) output motor cables by a minimum distance of 300 mm (12 inches).
5. Ensure the differential output leads (A, A-not, B, B-not) are terminated into a matching 5 VDC differential receiver input to preserve signal square-wave integrity.