Opticon NFT 1125 - Manual (Page 16)

Manual No. 25-NFT1121-01
Series NFT-1121/2135 Mini CCD Fixed Position Scanners
Measuring Scanner Performance
Two methods are helpful in determining the optimum position of the scanner. The first method is to program
the scanner for Trigger Disable and Continuous Read modes. The scanner will be always on and will
continuously read the same bar code. Since the buzzer sounds each time the bar code is read, the sound of
the buzzer can be used like a “Geiger counter” (as the position of the scanner changes, the sound of the
buzzer will change). The buzzer sound will be loudest and most continuous at the best reading positions.
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 100 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 100 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.
Here’s how to perform the Read Rate Test:
1) Program the scanner for Continuous Read (S2) and Trigger Enabled (S8).
2) Instruct the scanner to enter the Read Rate Test mode (ZA).
3) Locate the scanner in the desired position relative to a test bar code then enter a Z command. The
scanner will read the bar code once and store it in memory.
4) Enter another Z command. The scanner will scan the bar code 100 times and then transmit the Read
Rate Percentage to the host.
5) Steps 3 and 4 can be repeated as often as desired, moving the scanner to new locations before each
test.
6) Exit the Read Rate Test mode (ZG).
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