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Section 3 - Positioning the Scanner
V520-LHA7127
Application Notes
Tips for Achieving High Throughput
In some applications your primary objective may be to achieve the highest possible throughput rate. The
following list identifies the parameters and scanner settings that can maximize scanning and decode
throughput speed.
Note
By emphasizing maximum throughput, other areas of performance may be
affected. For example, the number of non-reads could increase.
If high throughput is critical, consider some or all of these settings:
• Operate in the Trigger Disabled mode. Operation of the trigger can require as much as 200 msec before
decoding begins, slowing down throughput rate.
• Only enable those symbologies that you will be decoding.
• Eliminate all suffixes and prefixes.
• Minimize the number of redundant reads required before transmitting data.
• Transmit the decoded data at the highest baud rate, 38,400 baud.
• Disable buzzer functions.
Tips for Insuring Highest Data Integrity
There are several parameters that can enhance your confidence that the correct bar code data is transmitted.
Note
By emphasizing the accuracy and security of the data, other areas of the
scanner operation may be affected. For example, you may not achieve the
highest throughput.
If accuracy and data integrity are critical, consider some or all of these settings:
• Program the scanner to require a high number of redundant decodes prior to transmitting. For example,
program the scanner to decode a bar code exactly the same way three consecutive times before
transmitting the data. Then decoding the bar code the same way 2 out of 3 times or any 3 out of 4 times is
not sufficient. It must obtain three consecutive and identical decodes.
• Utilize a predetermined, fixed-length of bar code. Program the scanner to only decode a bar code of that
length. Bar codes of any other length will be ignored.
• The quality of the printed bar code must be excellent.
• Use a bar code symbology that contains an internal check digit and program the scanner to calculate that
check digit for validity prior to transmitting.
• Do not use a symbology with poor internal verification, or subject to partial decodes, such as 2 of 5 or MSI/
Plessey.
• Only enable those symbologies that you will be decoding.
• Transmit data at low baud rates to minimize communication errors.
Enable the “Number of Characters Transmitted.” The scanner will calculate and transmit a number indicating
the total number of characters it is transmitting. Your host application program can compare this number with
the actual number of characters received to verify that the correct amount of data is received.
Summary of Contents for V520-LHA7127
Page 1: ...MANUAL USER Cat No Q07BAZ1 V520 LHA7127 Miniature High Speed CCD Fixed Position Scanner...
Page 2: ...V520 LHA7127 Miniature High Speed CCD Fixed Position Scanner User Manual...
Page 3: ...iv...
Page 9: ...x Application Precautions 3...
Page 25: ...16 Section 4 Configuring the Scanner V520 LHA7127...
Page 27: ...18 Section 5 Application Engineering Support V500 LPN5627 V500 LPR5627...
Page 29: ...20 Section 6 Scanner Servicing and Maintenance V520 LHA7127...
Page 69: ...60 Appendix B Dimensional Drawings V520 LHA7127...
Page 71: ...62 Appendix C Optical Performance Charts V520 LHA7127...
Page 75: ...66 Appendix D PLC Touchscreen Connection Examples V520 LHA7127...
