Encoder Technical Specifications
When selecting and integrating an encoder, correctly interpreting its datasheet is critical. A datasheet not only lists the product’s performance specifications but also defines the test conditions and operating limits. The guide below provides an extremely detailed and professional set of specification fields to help engineers precisely filter and compare a wide range of products.
1. Datasheet Structure & How to Read
- Product Overview: Model Number, Series Name, intended application, mechanical style
- Electrical Characteristics: Supply Voltage, Output Types, Current Consumption, protection features
- Mechanical Characteristics: Resolution, Accuracy, Shaft Diameter, mounting style, Bearing Life, Mass & Moment of Inertia
- Environmental & Reliability: Operating Temperature, Humidity, IP Rating, Vibration, Shock, EMC Emission/Immunity
- Communication & Interface: Incremental Output, Absolute Interface, Fieldbus Protocols, Ethernet Protocols
- Functional Safety & Approvals: Safety Level, Diagnostics coverage, CE/UL/ATEX approvals
- Accessories & Options: Cables, connectors, flange kits, couplings, mounting hardware
- Dimensions & Wiring Diagrams: Outline drawings, installation diagrams, wiring schematics
Tip: Always verify the “Test Conditions” (temperature, load, scan rate, etc.) to avoid misinterpreting spec values under different conditions.
2. Core Specification Fields
2.1 Product Identification
| Field | Example | Notes |
|---|---|---|
| Model Number | ENC‑X12‑2048‑T | Series (ENC‑X12), Resolution (2048 PPR), Interface (TTL) |
| Series Name | X12 | Family identifier for quickly grouping similar products |
2.2 Electrical Characteristics
| Field | Unit | Example | Notes |
|---|---|---|---|
| Supply Voltage | VDC | 5 ± 5 % | Recommended operating voltage and tolerance |
| Start‑Up Voltage | VDC | ≥ 4.5 | Minimum voltage required for reliable start |
| Current Consumption | mA | ≤ 100 | Operating current (excluding external load) |
| Ripple & Noise | % pp | ≤ 5 % | Power-supply ripple and noise |
| Reverse Polarity Prot. | — | Yes | Protection against reverse wiring |
2.3 Output Signals
| Field | Unit | Example | Notes |
|---|---|---|---|
| Output Type | — | TTL Push‑Pull | Incremental square‑wave output, push‑pull drive |
| Logic Levels | V | Low 0–0.8 / High 2.4–5 | TTL logic voltage levels |
| Output Impedance | Ω | 100 | Push‑pull output impedance |
| Differential Output | — | RS422 | Differential signaling for noise immunity |
| Zero Pulse Width | µs | 10 | Width of the index (Z) pulse |
2.4 Power & Thermal
| Field | Unit | Example | Notes |
|---|---|---|---|
| Operating Power | W | 0.5 | Average power consumption during normal use |
| Peak Power | W | 1.0 | Instantaneous peak power at start‑up/high load |
| Thermal Resistance | °C/W | 50 | Junction‑to‑Case or Junction‑to‑Ambient thermal resistance |
2.5 Mechanical Characteristics
| Field | Unit | Example | Notes |
|---|---|---|---|
| Resolution | PPR | 2048 PPR / 13 bit | Incremental / Absolute resolution |
| Accuracy | arcsec | ± 30 | Maximum angular deviation |
| Repeatability | arcsec | ± 5 | Repeatability precision |
| Shaft Diameter | mm | 6 | Solid‑shaft diameter |
| Shaft Tolerance | h6/h7 | 6h6 | Mechanical tolerance class |
| Radial Load | N | 20 | Maximum radial load |
| Axial Load | N | 10 | Maximum axial load |
| Bearing Life | hours | ≥ 1×10⁷ | L₁₀ life at rated load & speed |
| Mass (Weight) | g | 120 | Body weight |
| Moment of Inertia | g·cm² | 10 | Rotational inertia |
2.6 Environmental & Reliability
| Field | Unit | Example | Notes |
|---|---|---|---|
| Operating Temp | °C | -20 to +85 | Operating temperature range |
| Storage Temp | °C | -40 to +100 | Storage/transport temperature range |
| Humidity | % RH | 5 to 95 | Relative humidity, non‑condensing |
| Vibration | g, Hz | 10 g, 10–2000 Hz | Random vibration test |
| Shock | g | 50 | Peak shock tolerance |
| IP Rating | — | IP65 / IP67 | Dust/water ingress protection |
| EMC Emission | dBµV | CISPR 22 Class B | Electromagnetic emissions |
| EMC Immunity | kV, V/m | IEC 61000‑4‑2 4 kV | ESD and field immunity |
2.7 Communication & Interface
| Field | Unit | Example | Notes |
|---|---|---|---|
| Incremental Output | — | A/B/Z | Standard incremental channels |
| Absolute Interface | — | SSI, BiSS‑C | Synchronous serial protocols |
| Fieldbus Protocols | — | CANopen, EtherCAT | Multi‑node fieldbus networks |
| Connector Type | — | M12 8‑pin | Cable connector style |
| Cable Length | m | 2 / 5 / Custom | Standard and optional lengths |
2.8 Functional Safety & Approvals
| Field | Unit | Example | Notes |
|---|---|---|---|
| Safety Level | — | SIL2 / PL d | Functional Safety integrity level |
| Diagnostics | % | 99 | Diagnostic coverage percentage |
| Approvals | — | CE, UL, RoHS | Regulatory approvals |
2.9 Accessories & Options
- Standard Cable: PVC/PUR jacket, 2 m length
- Optional Flange Kits: Synchro flange, servo‑clamp flange, multi‑hole mounting plate
- Connectors: M12, M23 or custom waterproof aerospace connectors
- Firmware Settings: Resolution, rotation direction, filtering adjustable via software
3. Comparison & Reference Tips
- Test Conditions: Spec values are measured under specific conditions; always check footnotes or the “Test Conditions” section.
- Rated vs. Maximum: Distinguish between continuous rated limits and short‑term peak limits.
- Dynamic vs. Static: Accuracy, thermal drift, and shaft run‑out may differ when running versus stopped.
- Multi‑Vendor Comparison: Use a consistent template to list products side‑by‑side for quick core spec comparison.
4. Complete Specification Template Example
| Parameter | Unit | Value / Notes | Description |
|---|---|---|---|
| Model Number | — | ENC‑X12‑2048‑T | 2048 PPR, TTL Incremental Encoder |
| Supply Voltage | VDC | 5 ± 5 % | TTL standard |
| Operating Current | mA | ≤ 100 | |
| Output Type | — | TTL Push‑Pull, RS422 | Incremental A/B/Z |
| Resolution | PPR | 2048 | |
| Accuracy | arcsec | ± 30 | Over full temperature range |
| Repeatability | arcsec | ± 5 | |
| Max. Speed | RPM | 6000 | |
| Shaft Diameter | mm | 6 | Solid shaft |
| Radial Load | N | 20 | |
| Axial Load | N | 10 | |
| Bearing Life | hours | ≥ 1×10⁷ | L₁₀ @ rated load & speed |
| IP Rating | — | IP67 | |
| Operating Temperature | °C | -20 to +85 | |
| Interface | — | SSI, CANopen | |
| Safety Level | — | SIL2 / PL d | |
| Approvals | — | CE, RoHS, UL |
By leveraging these detailed fields and templates, you can swiftly locate and understand the core parameters in any encoder datasheet—ensuring accurate selection, seamless integration, and reliable, long‑term operation in industrial automation systems.