VG Virtual Absolute Decoder0 pages

"Gurley Model VGVirtual Absolute Decoder nn

For Use With:Model 7700Output:Max Resolution:MultiplexedNatural Binary 14 bits (16,384) Virtual Absolute

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Small Package - Big Performance

Virtual Absolute The VG Virtual Absolute technology is a unique encoding method that combines the opto-mechanical simplicity of an incremental encoder with the system reliability and interfacing ease of an absolute encoder. Please refer to the decoder is used with the Model 7700 Model 7700 modular encoder to form an absolute rotary or linear system with resolution up to 12 bits (14 bits is optional). GPI's data sheet for full details on the encoder.The disc or scale in a Model VG provides patented high-speed circuitry to decode the special serial index track and interpolation to increase the final resolution up to 12 bits total. In addition to the natural binary position output, a Status bit tells you when the encoder is initialized. This bit is at a logic high whenever the supply voltage has been interrupted, when the initializing motion is not yet complete, or when some other effect such as electrical noise, damage, or fouling of the disc interferes with the proper code sequence from the index track. When these self-tests are all satisfied and the encoder is initialized, the Status bit is low, indicating the position data output is valid. Virtual Absolute (VA) encoder is similar to an incremental disc or scale in that both contain a cyclic track and an index track. In an incremental encoder, the index occurs at one place in the full travel, but in a VA encoder, the index track is a continuous serial code (similar in appearance to a bar code). You don't know position immediately upon power-up, as you do in a conventional absolute, but after a very short travel, in either direction and starting from anywhere, you know exactly where you are. The >

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ISO 9001 Certified

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Gurley Precision Instruments514 Fulton StreetTroy, NY 12180 U.S.A.(800) 759-1844, (518) 272-6300, fax (518) 274-0336, Online at www.gurley.com, e-mail: info@encoders.com ingenuity@work

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