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Heidenhain encoder spares: the model name is not enough

An LS, LC, ERN or EQN on the label names a family, not a part. Why the ID number, the measuring length or line count and the interface decide whether a spare fits, and what Heidenhain says about successors.
Author
Sparehawk
Reading time
3 min read
Published
  • Maintenance
  • Part numbers

A Heidenhain spare fits when four things on its label match the old encoder: the model, such as ERN 1387; the ID number with its two-digit variant, such as 540739-02; the line count or measuring length; and the interface, such as 1 Vpp, TTL or EnDat. The model name alone only names the family. Two encoders with the same model can carry different ID numbers and not interchange.

Heidenhain encoders tell the control where an axis is. When one fails, the machine stops, and the spare has to report position exactly the way the old one did: same signal, same resolution, same length or line count. The model name on the label (LS 187, ERN 1387, EQN 1325) names the family; the ID number and the rest of the label name the part.

The families

  • Linear encoders. LS (sealed, incremental) and LC (sealed, absolute) for machine axes; LB, LF and LIP for longer axes and higher accuracy.
  • Rotary encoders. ERN and ROD (incremental), ECN and EQN (absolute, single-turn and multiturn), and ROC and ROQ (absolute).
  • Angle encoders such as ERM for rotary tables and spindles.
  • Controls and electronics. TNC controls, EXE interpolation electronics and the boards inside the controls.

Incremental encoders send counting signals, and the axis must home after power-on; absolute encoders report the position directly. Swapping one for the other changes the control’s configuration, not just the encoder.

What the label carries

  • The model, for example ERN 1387.
  • The ID number: a number with a two-digit variant after the dash, for example 540739-02 or 1223032-01. Two encoders with the same model can have different ID numbers, because the variant fixes things the model name does not.
  • The line count or measuring length: 2048 lines on a rotary encoder, the measuring length in millimetres on a linear one.
  • The interface, for example 1 Vpp, TTL or EnDat. The control expects one of them.

Quote all four in a request. A spare with the right model and the wrong ID number may mount and still not work.

Successors are planned, and often mounting-compatible

Heidenhain plans its successors with existing machines in mind. Its service team gives the LC 1×3 and LC 4×3 linear encoders as an example: discontinued for replacement sales at the end of 2018 and replaced by the LC 1×5 and LC 4×5, which are fully mounting-compatible and fit the same hole pattern. So when the exact part is no longer sold new, ask Heidenhain for the successor of your ID number before you assume a retrofit, and compare it with a used or refurbished unit of the original.

Searching for a Heidenhain spare

Search by the model as it appears on the label, for example LS 187 or ERN 1387, or by the ID number. Spaces do not matter. The same works for every family above, from LC and LIP linear encoders to EQN and ROQ rotary encoders, ERM angle encoders, TNC controls and EXE electronics. To see the whole range, browse all Heidenhain parts.

Each offer states its condition: new, new surplus, refurbished or used. For an encoder, the condition decides what you should ask the supplier before you order.

Before you order

  • Photograph the label of the old encoder, all of it.
  • Note the cable and connector. Length and connector type are part of the variant.
  • For a linear encoder, measure the mounting if the label is unreadable: the measuring length and the hole spacing narrow it down.
  • Ask what was tested on a used or refurbished encoder, and on what. Refurbished, surplus and used and warranty on surplus parts list the questions.

Not listed? Send a request with the label photo: how requests work.

01

Frequently asked questions

1.1

Can I replace a Heidenhain encoder with one of the same model but a different ID number?

Not safely. The ID number and its two-digit variant fix details the model name does not, such as cable, connector and signal. A spare with the right model and the wrong ID number may mount and still not work.
1.2

What should a request for a Heidenhain encoder include?

The model, the full ID number with its variant, the line count or measuring length, and the interface, such as 1 Vpp, TTL or EnDat. Add a photo of the whole label and note the cable length and connector type.
1.3

Can an incremental encoder replace an absolute one?

Not as a like-for-like spare. An incremental encoder sends counting signals and the axis must home after power-on; an absolute encoder reports the position directly. Swapping one for the other changes the control’s configuration.
1.4

What replaced the Heidenhain LC 1×3 and LC 4×3 linear encoders?

According to Heidenhain’s service team, the LC 1×5 and LC 4×5. The older encoders were discontinued for replacement sales at the end of 2018, and the successors are fully mounting-compatible and fit the same hole pattern.
1.5

How do I identify a linear encoder whose label is unreadable?

Measure the mounting. The measuring length and the hole spacing narrow down the model, and a photo of the cable and connector helps a supplier confirm the variant.
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