Omron V520-LHA7127, User Manual

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Section 3 - Positioning the Scanner
V520-LHA7127
The Read Rate Test
The second method, the Read Rate Test, provides a mathematical calculation of scanning performance. In this
test the scanner scans a bar code 700 times and then calculates the number of those scans that resulted in a
good decode. That number, expressed as a percentage, will be transmitted to the host. For example, 93%
means that the scanner decoded the bar code symbol 93 times out of the 700 scan attempts. By performing
the Read Rate Test with the scanner mounted in various positions you can determine which of those locations
results in the best performance.
How to Perform the Read Rate Test
Perform the following steps after you have correctly configured communications to the computer via your
RS-232C port and power is made available to the scanner:
Send the command: <Escape> U8 <Carriage Return>
Note Be sure to use capital letters, e.g. “U8,” not “u8.”
The scanner will read the barcode continuously and will display the ratio of the number of successful reads to
the total number of attempts.
The printout on the screen will appear as follows:
(Example)
700d OK 93.5%
CODE-39 TEST
The number in the upper left indicates the number of times the decoder ran while scanning at 700 scans per
second. The number can be lower than 700 when reading noisy barcodes. The upper right percentage
indicates the ratio of the number of successful reads to the total number of attempts. By positioning the
scanner at the optimal distance from the barcode with the correct orientation and with a grade-A quality
barcode, readings of 95% or higher are expected. Reset the scanner after testing.