Advanced Micro ControlsNR25F-B1E2AE04Networked Absolute Multi-Turn Rotary Encoder, 28-Bit (65,536 Counts/Turn x 4,096 Turns), EtherNet/IP & Modbus TCP, 3/8 in Solid Shaft, 2.65 in Square Flange, IP67

Product Description

What this part is

An AMCI NR25-series networked absolute rotary shaft encoder. It is not a pulse-counting incremental encoder: it reports true absolute position over an industrial Ethernet network, so the machine knows where it is the instant power returns — no homing routine, no reference run, no lost position after a fault.

Decoding the order code NR25F-B1E2AE04

AMCI builds the NR25 to a seven-field configuration code. This unit decodes as follows, per AMCI’s own part-number builder:

NR25 — 2.5 in diameter networked encoder package.F — 2.65 in square flange mounting.B — Nitrile shaft seal, powder-coated aluminium housing.1 — 3/8 in diameter solid stainless shaft, 0.875 in long, no flat.E — Ethernet interface (EtherNet/IP and Modbus TCP capable hardware).2 — 28-bit multi-turn output: 65,536 counts per turn across 4,096 turns.A — EtherNet/IP output code (the protocol this unit is configured to speak).E04 — End-mounted connectors, two of them: one carries data, or data and power together via Power over Ethernet; the second supplies auxiliary power if PoE is not used.

Why the 28-bit / 4,096-turn choice matters

AMCI offers three output configurations on this body: 16-bit single-turn, 28-bit multi-turn (4,096 turns) and 30-bit multi-turn (16,384 turns). Single-turn units lose the revolution count, so they only suit rotary axes that never need to know how many turns have accumulated. This is the middle option — full 16-bit resolution within a turn, plus a 12-bit revolution counter. That combination is what makes it usable on a ballscrew, a hoist, a winder or an indexing table where total travel spans thousands of revolutions. If your application needs more than 4,096 turns of range, the -3 (30-bit) variant is the one to specify; do not assume this unit will cover it.

Power and the PoE decision

The Ethernet NR25 accepts 12 to 54 Vdc, drawing 2.5 W maximum (100 mA at 24 Vdc). With the E04 end-connector option you have a genuine choice at commissioning: run one cable and let a PoE (mode A) switch or injector feed the encoder, or run conventional 24 Vdc into the auxiliary power connector and keep the network cable data-only. The single-cable PoE route is why the E04/S02 options exist and it is the main reason integrators pick the NR25 over a discrete-wired absolute encoder — one drop instead of two.

Programmable over the network

Direction of increasing counts (default clockwise viewed at the shaft), counts per turn, velocity units, the preset/zero function and the total measurement range at which position rolls over to zero are all set over the network rather than by DIP switch. An optional time-stamp word can replace the velocity word in the input assembly; it is an unsigned double integer with a 400 ns interval that rolls over every 1,717.9869184 seconds. Being EtherNet/IP, it follows ODVA guidelines and adds to a compatible PLC/PAC via an EDS file.

Mechanical and environmental

Powder-coated aluminium housing, IP67. The 3/8 in solid shaft is rated 40 lb radial / 20 lb axial maximum, with bearing life quoted at a minimum 2 x 10^9 revolutions at maximum shaft load. Starting torque is 2.0 oz-in maximum at 25 °C and rotor moment of inertia 6.00 x 10^-4 oz-in-sec². Because it is flange-mounted with a solid shaft, it needs a flexible coupling — do not hard-couple it to a driven shaft or the radial rating will be exceeded by misalignment alone.

What is and is not included

Encoder only. Mating M12 cordsets, PoE injector, flexible coupling and mounting hardware are not part of the AMCI order code and are not included. The EDS file is a free download from AMCI.

Fitting and interchange notes

The nitrile seal (B) is the standard choice; specify C or V for Viton if the encoder will sit in aggressive coolant or solvent. Housing material is the other half of that same code character — A and C are stainless steel bodies for washdown and food-contact duty, B and V are aluminium. Within the NR25 family the mechanical envelope is shared, so an F-flange aluminium body with a 3/8 in shaft is dimensionally interchangeable across interface and protocol variants; the electrical half of the code is what must match your network. AMCI also builds an NR25 networked resolver in the same 2.5 in package for applications where a resolver’s ruggedness is preferred over an optical encoder. Product remains in current AMCI production.