4 - 14 2020/4820/4820 i User’s GuideDecode Search ModeThere are two selectable decode (scanning) modes:Full Omnidirectional - Searches for barcode features beginning at the center ofan image, and searches to the image’s limits. This mode reads all symbologies(including OCR), in any orientation. The Full Omnidirectional search is verythorough which may slow performance time.Note: This search mode is the default setting for the image scanner.Quick Omnidirectional - This is an abbreviated search for barcode featuresaround the center region of an image. This mode quickly reads all symbologiesin any orientation. The Quick Omnidirectional mode may miss some off-centersymbols, as well as larger Data Matrix and QR Code symbols.Preferred SymbologyNote: Does not apply to OCR.The 4820/4820i can be programmed to specify one symbology as a higherpriority over other symbologies in situations where both bar code symbologiesappear on the same label, but the lower priority symbology cannot be disabled.For example, you may be using the imager in a retail setting to read UPCsymbols, but have occasional need to read a code on a drivers license. Sincesome licenses have a Code 39 symbol as well as the PDF417 symbol, you canuse Preferred Symbology to specify that the PDF417 symbol be read instead ofthe Code 39.Preferred Symbology classifies each symbology as high priority, low priority,or as an unspecified type. When a low priority symbology is presented, theimager ignores it for a set period of time (see Preferred Symbology Time-out onpage 4-16) while it searches for the high priority symbology. If a high prioritysymbology is located during this period, then that data is read immediately.If the time-out period expires before a high priority symbology is read, the imagerwill read any bar code in its view (low priority or unspecified). If there is no barcode in the imager’s view after the time-out period expires, then no data isreported.Full OmnidirectionalQuick Omnidirectional
