Skip to content

Enclosed linear encoder

Renishaw FORTiS-S

Standard-width (37 mm extrusion) enclosed absolute linear encoder built for contaminated machine tool environments, with lip seals and optional air purge. Uses non-contact absolute readhead technology and drive-specific serial protocols.

Key specifications

Ingress protectionIP53 installed; IP64 with air purge
Linear speed (max)4 m/s
Resolution (finest)0.5 nm
AccuracyStandard ±5 µm; High ±3 µm (high grade up to 3040 mm)
InterfaceBiSS C, BiSS Safety, FANUC, Mitsubishi, Panasonic, Siemens DRIVE-CLiQ, Yaskawa

Summarised in our own words from Renishaw plc's published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2 · Source 3

Notes on this data

Measuring lengths 140-4240 mm. Resolutions 0.5, 1, 1.25, 10, 12.5, 25, 50 nm. Vibration <300 m/s² (IEC 60068-2-6), shock 11 ms <300 m/s². Operating 0 to 50 °C. FS variant: ISO 13849 PLd, IEC 61508 SIL2. BiSS Safety on FS variant; DRIVE-CLiQ via external interface.

Specify Motion is not affiliated with Renishaw plc. Renishaw and FORTiS-S are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

Typical applications

Machine toolsFully closed-loop servo axesGlass scale replacementHarsh/contaminated environments

Alternatives that meet or exceed these figures

Engineers often come to us with a Renishaw part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.

Magnetic linear encoder

Bogen ALS21

Meets or exceeds on the published figure compared

Absolute linear magnetic read head for LMSA scales, 1 µm resolution, IP67.

Published maximumFORTiS-SALS21
Speed4 m/s15 m/s meets or exceeds
View ALS21 →
Magnetic rotary encoder

Bogen IKS23

Meets or exceeds on the published figure compared

Rugged incremental head with RS422 or HTL output and 10-30 VDC supply option. Works on linear and rotary scales.

Published maximumFORTiS-SIKS23
Speed4 m/s16 m/s meets or exceeds
View IKS23 →
Capacitive linear encoder

KappaSense FREEe

Meets or exceeds on the published figure compared

Capacitive absolute linear encoder with a passive 3 g read head and no moving cables; several heads can share one scale.

Published maximumFORTiS-SFREEe
Speed4 m/s6 m/s meets or exceeds
View FREEe →

Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.

Other enclosed linear encoder series

Spec builder

Specify what you need instead of FORTiS-S

Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.

  1. 1Products
  2. 2Performance
  3. 3Environment
  4. 4Volumes
  5. 5Your spec
Step 1 of 5

Engineer support

Let our experienced engineers do the hard work for you

Tell us how you use the Renishaw FORTiS-S: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.

  • Reviewed by an engineer, not an autoresponder
  • Like-for-like and better-fit alternatives
  • Standard, modified and custom options

Prefer to configure it? Use the spec builder.

We use your details to answer this enquiry and share them with the specialist engineering and supply partner best placed to fulfil it. See our privacy notice.

Ask an engineer