CS64A Color Sensors 010627a (Address updated)
Contents 1. Specifications ............................................................................... 4 1.1 2. Ordering Information................................................................. 4 Introduction ................................................................................. 5 2.1 3. Primary Features........................................................................ 6 Mounting the CS64A................................................................... 7 3.1 3.
1. Specifications Model Sensor-to-Object Standoff Distance Sensor-to-Object Sensing Range Sensing Area Response Time Output Update Rate Analog Outputs Color 1 Color 2 Color 3 Color 4 Calibration At Standoff Distance Ratio Variation with Sensing Distance Temperature Stability Supply Voltage Current Consumption Enclosure Environment CS64A-00 CS64A-02 1.75 to 2.0” (454.75 to 5.0” (12050mm) optimum 125mm) optimum 1.25” (32mm): 1.25 to 1.25” (32mm): 4.25 to 2.5” sensor-to-object 5.0 sensor-to-object 0.
Introduction The CS64A color sensor contains a light generation system to illuminate the object to be sensed, and a light receiving system to read the diffuse reflected light from the object. The light generation system consists of four sets of light emitting diode (LED) light sources—a total of 28 LEDs. The CS64A determines color by turning on just one set of LEDs (one color) at a time and analyzing the light captured by it’s precision silicon photodiode.
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2. Mounting the CS64A In general, the sensing area should be as dark as possible (especially if small differences in color are to be detected). Any light that is in the sensing area that is not generated by the CS64A is a source of error. The Blue and Green colors are more sensitive to extraneous light than are the Red and NIR colors since these LEDs are less intense.
2.1 Moving Line Applications In cases where the product moves under the sensor as on an assembly line, it is usually important not to overly restrict headroom (distance from sensor to the target object). 2.1.1 Adequate space and moderate light levels (normal factory lighting, no direct sunlight) It is usually adequate to use a plate mounted above the line at a distance approximately equal to the sensor standoff distance (~2” for the CS64A-00).
inside dimensions of the rectangular could be a small as 3/4” by 4”, although 1” x 4 ½” would be preferable. Flat black surfaces are especially important with these smaller inside dimensions. Top View: CS64A with Light Block Tube CS64A-00 Color Sensor Side View: CS64A with Light Block Tube Light Block Tube Color Sensor Optional seal or weather-stripping Light Blocking Tube – 4” x 6” inside Inside of tube to be flat black Target Object 2.2.
3. Wiring the CS64A The CS64A requires a 24Vdc power source capable of supplying 100mA. It should be a linear power supply and not be used to supply other loads. A 250mA fast blow fuse should be used between the power supply and the sensor. The power supply voltage must be maintained within 5% (22.8 to 25.2V) at the sensor. A P6KE30A Transzorb protects against overvoltage and reverse voltage. This device limits the working voltage to a maximum of 25.6 volts.
4. Adjustment The CS64A-00 is factory calibrated to read Spectralon as 9.50V on all four colors (100% ratios) at 1.75” standoff. (Refer to specification table for standoff distance for other models). Spectralon has >99% reflectance over the visible/NIR spectrum. (The 9.50V setting ensures that the outputs do not exceed 10V over the full sensing range). You can either maintain this calibration or match the calibration to your application.
5. Sample Quick Test You can do a quick test using the CS64A simply by wiring the +24V power, placing the samples one at a time at the standoff distance (1.75 to 2 inches from the bottom of the CS64A-00), recording the analog readings, and calculating the ratios on a calculator: Measure Sample NIR Red Calculate Green Blue Red/NIR Grn/NIR Blu/NIR 1 2 3 4 5 6 7 8 9 10 11 12 Differences in the Red/NIR, Green/NIR and Blue/NIR ratios are used to differentiate between colors.
6. Threshold Setting To differentiate between colors, set up thresholds on the Red/NIR, Green/NIR, and Blue/NIR ratios. If a sample is different from every other sample in one of the ratios, a set of thresholds (upper and lower) on that ratio can sort that color from all of the others.
7.2 Edge Effects The CS64A-00 sees an area of about 0.35 x 0.35 inches. When material is entering or leaving the sensing area, the color can appear wrong for a variety of static and dynamic conditions. For best results, read the analog outputs and compute the color only when the CS64A sees the intended material over the entire viewing area. 7.3 Angle of CS64A to Material The most consistent readings are obtained if the material is perpendicular to the CS64A in both planes.
8. Recalibration The LEDs have a typical operating life of 100,000 hours or about 10 years of continuous operation. The intensity of LEDs varies with temperature and aging due to the properties of the semiconductor materials used. The CS64A sensors use feedback circuitry to maintain amplitudes over a wide range of temperature and to compensate for LED aging. The automatic compensation will not eliminate 100% of the variation, so calibration should be checked regularly.
10. Frequently Asked Questions Q. How many different colors can the CS64A detect? A. Unlike many color sensors, the CS64A does not limit the number of sorting outputs. The CS64A, when used with a host PLC or computer with math capabilities, can sort into virtually unlimited categories. Q. What if my materials are textured? A. The CS64A has been very successful in handling a variety of textured, grainy, and other difficult surfaces where other color sensors give inconsistent readings. Q.
A. In PLC sorting applications, the host system typically reads the four 0-10V signals and sets thresholds on the Red/NIR, Blue/NIR, Green/NIR ratios and NIR amplitude readings as needed. (Usually not all four are required in a given application). Using ratios compensates for most variations caused by sensor-to-target distance changes and dust on the sensor window. Q. Does the CS64A require special lighting? A. No additional lighting is required.
1602 Ultra-flat black. Some materials and finishes may provide acceptable performance without painting. They may not be obvious, however black anodized aluminum reflects in the near-infrared spectrum, for example, and should not be used without painting. The CS64A can be used to test materials—look for very low readings on all four outputs. A slot is a good way to eliminate ambient light, and soft weather-stripping or brush can be used to seal the bottom if required. Q.
color sensor will require periodic calibration checks, this can typically be done at widely spaced intervals with the CS64A. The drift of demo units is not representative of the performance of production units. Q. What are the limitations to the detection of colors? A. The measurement consistency varies from application to application. Here are the various error sources associated with any color sensor, including the CS64A. Sample color variations: Often colors vary from sample to sample.
11. Troubleshooting The CS64A's output indicator LEDs provide helpful troubleshooting information. The green LEDs come on when the output voltage reaches approximately 2 volts and gradually increase in intensity as the output voltage increases, so they should be at least slightly on for all but very dark objects. If the green indicator LEDs are off (or very dim), when light colored material is in the normal sensing area, check for: 1. Dirt buildup on the window 2. Incorrect sensor to target distance 3.
14. Warranty The Products shall be free from defects in materials and workmanship under normal and proper use and service for a period of one (1) year from the date of shipment by DELTA. The obligation of DELTA under this warranty shall be limited to repairing or replacing the Product or any part thereof, which, in the opinion of DELTA, shall be proved defective in materials or workmanship under normal use and service during the warranty period.
Index Analog output, 5, 6, 10 Angle, 13, 14 Applications, 5, 14 Fixed, 8 Moving Line, 8 Black, flat, 8, 9, 11 Calibration, 4, 10, 11, 15 Material, 11, 15 Re-, 5, 11, 15, 18 Spectralon, 11, 18 Cleaning, 15 LEDs, 5, 6, 7, 13, 14, 15, 20 Aging, 5, 15 Operating life, 15 Light, extraneous, 7, 8 Mounting, 7, 8 Bellows, 9 Brushes, 8, 9 Curtain, 8 Light block plate, 8 Light block tube, 9 Near-infrared (NIR), 14 Amplitude, 12, 13 Purpose, 14 NEMA, 7 OEM package, 7 Orientation, 18 Power supply, 10 Ratios, 5, 13, 14 T
