VLM 500 Velocity & Length Measurement

The VLM500 works optically and contact-free. Based on a CCD sensor it implements the spatial filter principle. Spatial filter is the generic term for a measuring principle for the optical determination of velocity and length of moving objects. The spatial filter is based on the filtering effect of lattice-like structures (grid modulation). Basically, the functional principle of the VLM500 can be described as follows: The measuring object is projected on the CCD sensor which functions as an optical grid (no image taking). The VLM500 is equipped with an LED light source for the illumination of the measuring object. Due to the grid modulation a signal frequency, which is proportional to the speed, occurs upon movement of the object. The device calculates the velocity from the measured signal frequency. Several control circuits allow for automatic adjustment to most diverse materials. The VLM500 does not put high requirements on the surface character of the measuring object: Precise measurement is facilitated on periodic structures as well as on stochastic surfaces of metals, wood, rubber or paper.

Operating Principle:

CCD Sensor

Features:

•  Contactless optical
•  Velocity up to 50 m/s
•  Measuring uncertainty ±0.025 %
•  Working distance: 170 mm / 185 mm / 240 mm
•  Slip free
•  Nonwearing
•  Nearly material independent
•  High-Power illumination-LED
•  No harmful LASER-light
•  Robust and precise
•  Insensitive against impurity
•  Various interfaces
•  Easy installation
•  Nearly maintain free at a lifetime of > 15 years
•  PC-Software for parameterization
•  60 months warranty

Application:

• Able to measure on almost all surfaces and materials (e.g. metal, paper, textiles, plastics,      ceramic, wood, rubber)
• Suitable for various cases of applications (e.g. cutting, positioning, regulation,        inspection, quality control)
• Applicable for a wide range of product profiles (e.g. strips, rails, plates, foils, tubes,   cables, wires, robes, etc.)
• Length and speed measurement at winders, slitting lines, coating and inspection lines
• Velocity measurement in paper machines for example at paper pulp, web and paper
• Tube and profile length inspection and provision of velocity signals for testing purposes
• Velocity and cutting control for extruders

Specification:

• Measuring uncertainty 1) ±0.025 % at nominal working distance (±0.05 % in distance range and ±0.2 % in extended working range)
• Reproducibility 1) ±0.025 %
• Averaging-/Update-Time > 0.2 ms with additional 1 … 32 times sliding averaging
• Length measuring range Internal length range up to 1,000,000 km Detector / principle CCD sensor / spatial filter with semiconductor grid as reference
• Illumination White light LED (expected life span: > 5 years 2) , 70 % brightness after 50,000 hours of operation)
• Programming interface, isolated USB, isolated (for parameter setting, data output and firmware update)
• Opto-isolated outputs 3) ERROR Error Signal STATUS Signal status
• Opto-isolated inputs 4) TRIGGER 1, 2 External trigger signals DIRECTION External directional signal
• Pulse output (Encoder) A/B, 2 phases 90°, resolution 8 ns, 0.2 Hz … 50 kHz Optionally as Open Collector (IPPL), 5V active(IP5V) or Push Pull (IPPP)
• State indicator (LED on top of the VLM500) Signal (green), Error signal(red) , Communication (yellow), Forward(green), backward (green)
• Power supply, consumption 24 VDC, max. 25 W
• Temperature range 0 °C … 50 °C
• Protection class IP 65
• EMC Industrial standard in compliance with CE
• Weight, Housing dimensions ca. 3.3 kg, 260 mm x 160 mm x 90 mm (Standard model without connections; L series without lens window
• Optional Add-On cards on demand:
• I232 RS232: opto-isolated, usable like programming interface
• I485, I422 RS485 or RS422: opto-isolated, bus-compatible, usable like programming interface
• IAUN Analog interface, adjustable as 0 … 20 mA, 0 … 24 mA, 4 … 20 mA
• IFPB, IFFE, IFPN Profibus DP, FastEthernet (Telnet), Profinet
• Standard scope of delivery VLM500, power supply cable, connection cable, programming software (for Windows-PC), documentation
• Accessory (extract)
• Protective and cooling case CPC1 Mounting plate MPL