Professional Selection Guides & Technical Insights
Short answer: A FENAC part number is a fixed field string, so you cross-reference it field by field, never as a whole. The FNC 50, 58 and 100 families are still in production, so most retired units match inside the same family on flange letter, shaft or bore, resolution, channels and connection code. Change one field and it is a different encoder.
Most "discontinued encoder" jobs on FENAC units are not about a dead product line. FENAC still builds the FNC 16, 24, 30, 35, 40, 50, 58, 63, 80 and 100 families, the F82, the FHD H75 and H100 heavy-duty ranges and the FNCP programmable versions. What retires is a configuration: a resolution nobody orders, a cable length that changed, a flange variant that moved on. The work is reading the old number accurately and finding which field changed.
FENAC also publishes the numbering rules: its own FNC 58S datasheet carries a field table mapping every block of the part number, and the same grammar runs across the incremental families. Everything below comes from that datasheet and FENAC's current catalogue, so you can verify it before you order.
Take a real model from our own catalogue, FNC 58S 10630V2500-R2, against the field table in FENAC's FNC 58S datasheet:
| Field | Value | Meaning |
|---|---|---|
| Prefix + housing | FNC 58 | FENAC incremental encoder (FNCP = programmable), 58 mm housing. Housings: 16, 24, 30, 35, 40, 50, 58, 63, 80, 100 |
| Flange type | S | Servo flange (B = clamping, H = hollow shaft, E = end hollow shaft) |
| Shaft diameter | 10 | Solid shaft diameter or bore in millimetres: 4, 6, 8, 10 (others on request) |
| Output channels | 6 | 1 = A, 2 = AB, 3 = ABZ, 4 = AB+A'B', 6 = ABZ+A'B'Z' |
| Supply and output | 30V | 5V = 5 V in/out; 245V = 5-30 V in with 5 V out; 30V = 5-30 V in/out |
| Resolution | 2500 | Pulses per revolution (ppr), 1 to 65,536 ppr |
| Connection | R2 | R2 = radial 2 m cable, shield not connected (standard); connector codes: R1205, R1208, R1505, R1508, R1608, R2312 |
Read a second one, FNC 50H 8630V1024-R7: 50 mm housing, hollow shaft, 8 mm bore, 6 output channels, 5-30 V supply and output, 1,024 ppr, R7 connector. Same fields, same order — the grammar does not change between the 50 and the 58 family, which is what makes the cross-reference tractable.
The flange letter is the one field that decides whether the unit physically goes on. B is a clamping flange that mounts on a flange face and couples to a solid shaft; S is a servo flange with fixed servo mounting geometry; H is a hollow shaft that slides onto the shaft through its own bore with no coupling; E is an end hollow shaft through the housing rear.
A 58B and a 58S share the 58 mm housing, so they look like a family, but they are different mounting interfaces. If the old unit is a clamping flange and you order a servo flange of the same diameter, resolution and connection, it still will not fit. Because a hollow-shaft unit mounts on the shaft itself, bore diameter is the critical dimension there and no coupling is in the loop.
The long numeric run after the flange letter is four sub-fields stacked together, which is where most misreads happen. In 10630V2500 the blocks are 10 (shaft or bore), 6 (output channels), 30V (supply and output circuit) and 2500 (ppr). Compare 6630V1024: 6 mm shaft, 6 channels, 30V supply, 1,024 ppr. Two encoders ending in a familiar resolution can still differ in shaft diameter, which decides whether the unit fits at all.
| Sub-field | What changing it does |
|---|---|
| Shaft / bore (4, 6, 8, 10, 12, 14 mm) | Mechanical fit. A 10 mm bore will not grip an 8 mm shaft without a sleeve |
| Output channels (1, 2, 3, 4, 6) | Signal content. Dropping from 6 to 3 removes the inverted tracks |
| Supply and output (5V, 245V, 30V) | Electrical compatibility. 5V is 5 V in and out; 245V is a 5-30 V supply with a 5 V output; 30V is 5-30 V in/out. Feeding 24 V into a 5V unit is a failure |
| Resolution (1 to 65,536 ppr) | Scaling. It interacts with the drive's electronic gearing and any position or speed constant already commissioned |
Resolution is the field people fixate on, and it is usually the easiest to solve: a drive can often absorb a resolution change through its own scaling, while it cannot absorb a wrong bore or a wrong supply.
The suffix is the termination, and each variant has its own pin map. R2 is a radial 2 m cable with the shield not connected, the factory standard; R1205, R1208, R1505, R1508 and R1608 are connector variants in 5-pin and 8-pin form whose pin numbers differ by variant; R2312 is a 12-pin connector carrying the full channel set. Two encoders can be electrically identical on paper and still be wired differently at the plug, so check the datasheet table rather than the old cable.
In the 58 mm cable version the core colours are Brown +VB, White GND, Green A, Red A', Yellow B, Pink B', Gray Z and Blue Z', with the shield on Black — useful when re-terminating an old loom.
The table takes models we actually stock and shows how the reasoning runs when the original configuration has been withdrawn. Every part number is a real catalogue entry; where a field must change, the caution says why.
| Original model | Current match inside the family | Cautions |
|---|---|---|
| FNC 58B 10630V1024-R2 58 mm, clamping flange, 10 mm bore, 6 ch, 30V, 1,024 ppr, 2 m | FNC 58B 10630V1024-R2312L — same fields except the termination; or FNC 58B 10630V1000-R2 if a lower resolution works | The R2312L build is the same encoder with a 12-pin connector. Match flange, bore and channels first, then decide cable or connector |
| FNC 58S 10630V2500-R2 58 mm, servo flange, 10 mm shaft, 6 ch, 30V, 2,500 ppr, 2 m | FNC 58S 10630V2500-R2312L (identical except the connector); or FNC 58S 10630V2048-R2 if the drive is re-scaled | Moving 2,500 to 2,048 ppr means updating the electronic gearing and speed constants, then re-verifying direction |
| FNC 50B 8630V1024-R2 50 mm, clamping flange, 8 mm bore, 6 ch, 30V, 1,024 ppr, 2 m | FNC 50B 8630V1000-R2 or FNC 50B 8630V2000-R2 where resolution flexibility exists | The 50 family is narrower than the 58 in resolution range, so confirm your ppr is a listed option |
| FNC 100H3065V1024-R2 100 mm, hollow shaft, 30 mm bore, 6 ch, 5V, 1,024 ppr, 2 m | FNC 100HP 40330V1024-R2 is a sibling in the 100 family but a different build | Note the 5V supply field: this is not a 5-30 V unit, and 24 V will damage it |
Occasionally the original configuration is genuinely gone: an obsolete connector, a resolution outside the current option list, or a variant a machine builder specified once and never repeated. You then have two legitimate routes. Change the least damaging field — if flange, bore and supply all match and only the termination differs, order the closest current termination and re-terminate the machine side.
Or cross to another brand on a full specification match — defensible only when the mechanical and electrical interfaces both line up: housing and flange dimensions, shaft or bore diameter, resolution, supply voltage, output circuit and channel count. FENAC's 58 mm family alone spans 1 to 65,536 ppr, IP54 to IP67 and up to 10,000 rpm, so "same size" tells you very little. If the replacement changes ppr, the drive's gearing must be updated, or the machine will run correctly and position wrongly.
Ruilianxin Technology supplies genuine FENAC encoders sourced from the manufacturer or its first-tier distributors, with original packaging and traceable documentation. Send us the complete old part number and we will decode the fields, confirm which are still current, and quote the closest matching build. Single-piece orders are fine.
Read it as blocks. Take FNC 58S 10630V2500-R2, using the field table in FENAC's own FNC 58S datasheet: FNC is the brand prefix, 58 is the 58 mm housing, S is the flange type (S = servo, B = clamping, H = hollow shaft), 10 is the shaft diameter in millimetres, 6 is the output channel count (1 = A, 2 = AB, 3 = ABZ, 4 = AB+A'B', 6 = ABZ+A'B'Z'), 30V is the supply and output circuit, 2500 is the ppr, and R2 is the electrical connection (radial 2 m cable, standard).
FENAC's current catalogue still lists the FNC 16, 24, 30, 35, 40, 50, 58, 63, 80 and 100 families plus the F82, the FHD H75/H100 heavy-duty ranges and the FNCP programmable versions. If your unit is an FNC 50, 58 or 100, the family itself is alive, so the job is matching the fields.
No, not mechanically. Flange letters are physical interfaces: B is a clamping flange, S is a servo flange and H is a hollow shaft, and the three do not share mounting geometry. An H-variant mounts on the shaft through its bore, while a B or S unit mounts on a flange face and couples through a solid shaft.
Field mismatches that are easy to miss because the model number looks almost right. The three that cost the most downtime are the flange letter, the output channel count and the connection code. A 10630 model and a 6630 model differ in both shaft diameter and channel count, and R2, R7 and R2312 are three terminations with their own pinouts.
Sometimes, if it matches the mechanical and electrical interface at once: housing and flange dimensions, shaft or bore diameter, resolution, supply voltage, output circuit and channel count. FENAC's own 58 mm family spans 1 to 65,536 ppr with IP54 to IP67 protection and up to 10,000 rpm, so a cross-brand swap is a specification exercise, not a guess.
Give us the full model string from the nameplate. The Ruilianxin technical team will decode every field, flag the ones that have changed, and quote the matching current build.
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