Opticon NFT 2135, NFT 1125 manual Application Notes, Tips for Achieving High Throughput

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Manual No. 25-NFT1121-01

Series NFT-1121/2135 Mini CCD Fixed Position Scanners

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, 19200 baud.

Disable both the hardware and software buzzer functions.

If you need a buzzer, use the hardware buzzer rather than the software buzzer.

Tips for Insuring Highest Data Integrity

There are several parameters that can enhance your confidence that the correct bar code data is transmitted. Note that 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.

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Contents Series NFT 1125/2135 User’s ManualThis page left intentionally blank for repagenation Contents This page left intentionally blank for repagenation Organization of this Manual This page left intentionally blank for repagenation Product Overview Quick Start-Up ProcedureSection Introduction and Getting Started Page Physical Specifications Section Technical SpecificationsSymbologies Supported Optical SpecificationsRS232 Communications Specifications Electrical SpecificationsEnvironmental Specifications Connector Pin-OutsPage Getting Optimum Performance Section Positioning the Scanner Field-of-View Maximum Readable Bar Code Width LEDs Read Rate Test Measuring Scanner PerformanceTips for Insuring Highest Data Integrity Application NotesTips for Achieving High Throughput Tips for Verifying the Presence of a Bar Code Default Settings Section Configuring the ScannerProgramming Menus & Commands Page Technical Assistance and Support Section Application Engineering SupportCommon Causes of Poor Performance Modified and/or Customized ScannersPage Appendix a Programming Menus & Commands Index Programming via Bar Codes Programming via Computer CommandsIntroduction Page Computer Function Bar Code Command Description Global Default & Scanner ConfigurationsSymbology Selection Symbology Selection Add/Activate Specific Bar Code SymbologiesAdd/Activate Specific Bar Code Symbologies Delete/Deactivate Specific Bar Code Symbologies Options for UPC Options for Code Options for Codabar NW-7 Options for Codabar NW-7 5 Standard and Interleaved Format Options for 2CPN Options for IataFixing the Number of Digits Creating a Prefix and/or Suffix Setting Prefixes Identifying the Symbology Setting Prefixes Identifying the Symbology Setting Suffixes Identifying the SymbologySetting Suffixes Identifying the Symbology Direct Input of Numeric Characters Direct Input of Alpha Characters Direct Input of Control Characters Enable Number of Characters/Digits TransmittedSTART/END Enable Number of Characters/Digits TransmittedDisable Number of Characters/Digits Transmitted Communication Parameters Disable Number of Characters/Digits TransmittedCommunication Parameters Handshaking Buzzer Operation Buzzer Operation Positive & Negative Bar CodesSetting the Trigger Function Selecting the Read Mode Scanner Timeout Trigger Enabled Mode only Redundant Decoding STX?ETX for no read Transmitting Error Indications Trigger Enabled onlyPrint Quality Adjustments Page 1126/2126 Side View Appendix B Dimensional Drawings1127/2127 Front View Appendix C Optical Performance Charts