🧩 1. Determine the Output Type of the Measuring Grating
First, identify the signal type output by the grating scale:
| Output Type | Description |
|---|---|
| Square Wave (TTL/RS422) | Common A/B phase signals used for position and speed measurement |
| Analog Sine Wave | Requires a decoder to convert sine wave to square wave |
| Absolute Encoding | Usually serial communication (SSI, BiSS, SPI, CAN, etc.) |
🔌 2. Hardware Connection Method
1) A/B Phase Grating Connection to Host Computer
Typical wiring includes:
- A phase, B phase, Z phase (optional) connected to an intermediate controller or signal acquisition card
- Power lines: +5V / +12V / GND
Common hardware intermediary options:
| Solution Type | Function | Advantages |
|---|---|---|
| Encoder Acquisition Card (PCIe/USB) | Reads A/B phase signals, outputs displacement/speed | High precision, direct PC connection |
| Microcontroller / PLC | Counts A/B pulses, sends data via serial/USB | Low cost, flexible customization |
| FPGA | High-speed processing, multi-channel | Industrial-grade, complex but powerful |
🖥 3. Host Communication Interface
| Interface Type | Description |
|---|---|
| Serial Port (RS232/RS485/USB to Serial) | Used by microcontrollers and lower-level devices |
| USB | Encoder acquisition cards or USB DAQ modules |
| Ethernet | For high-speed industrial applications (EtherCAT/Modbus TCP) |
| CAN | Reliable real-time control in robotics or industrial bus |
💻 4. Host Software Integration
Common host-side software platforms include:
- LabVIEW: Ideal for visual monitoring and data acquisition
- MATLAB: Suitable for scientific analysis and processing
- Python / C# / C++: Flexible development for acquisition, visualization, and control
- SCADA platforms (e.g., MCGS, Kingview, WinCC): For industrial visualization
Data format handling:
- Incremental grating (A/B phase):
The host receives pulse count data, which is converted into displacement, speed, and direction using resolution and time interval settings. - Absolute grating:
The host reads the absolute position code directly.
✅ Connection Flowchart (Simplified)
Measuring Grating
↓
Signal Acquisition Module (e.g., MCU / DAQ Card / Decoder)
↓
Communication (Serial / USB / Ethernet)
↓
Host Software (LabVIEW / Python / MATLAB etc.)
🛠 Example Case: Incremental Grating + Microcontroller + Host PC
- The grating outputs A/B phase signals → STM32 microcontroller reads the pulses
- STM32 counts and sends real-time position and speed every second via serial port
- A Python application on the host computer receives serial data → displays real-time displacement curve
