Requirement: To support multiple scanners on the windows machine.
Tools:
Issue: The First scanner is claimed successfully. However, claim the second scanner leads to following exception "Device is already claimed by another control device".
Code Analysis:
SymScannerSvc112 as the service class being used for Handheld scanner.
SymScannerSvc112 extends SymScannerSvc. SymScannerSvc holds a static variable "_fClaimed".
When the first scanner is claimed, the static variable '_fClaimed' is set to true. Now, when you try to claim the second scanner, following code obstructs it as the '_fClaimed' is set as true.
Code: SymScannerSvc.java:
this._alreadyClaimed = false;
if(_fClaimed) {
this._alreadyClaimed = true;
this.release();
}
Note: 1. Scanners are attached to USB ports.
jpos.xml
<?xml version="1.0" encoding="UTF-8"?>
<JposEntries>
<JposEntry logicalName="ZebraScannerSerial">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra Serial" name="Zebra Serial Scanner on COM1" url="https://www.zebra.com"/>
<!--Other non JavaPOS required properties-->
<!--Scanner configuration-->
<!--Comm port device name-->
<prop name="port" value="COM1"/>
<!--Baud rate, default=9600, valid values are: 9600, 19200, 38400, 57600, 115200-->
<prop name="baud" value="9600"/>
<!--Data bits, default=7, valid values are: 5, 6, 7, 8-->
<prop name="databits" value="8"/>
<!--Stop bits, default=1, valid values are: 1=1 stop bit, 2=2 stop bits, 3=1.5 stop bits-->
<prop name="stopbits" value="1"/>
<!--Parity, default='O' (Odd), valid values are: 'N'one, 'O'dd, 'E'ven, 'M'ark, 'S'pace-->
<prop name="parity" value="O"/>
<!--Port mode, default='B', valid values are: 'B'=Nixdorf-B-->
<prop name="mode" value="B"/>
<!--UPC-A Length, default=13, indicates the number of digits generated by the scanner-->
<!--for UPC-A labels based on the scanner's preamble and check digit settings.-->
<!--The scanner service uses this value to determine when supplementals are present.-->
<!--The default value of 13 assumes preamble is set to system character-->
<!--and country code and that transmit check digit is enabled-->
<prop name="UPCALength" value="13"/>
<!--UPC-E Length, default=7, indicates the number of digits generated by the scanner-->
<!--for UPC-E labels based on the scanner's preamble and check digit settings.-->
<!--The scanner service uses this value to determine when supplementals are present.-->
<!--The default value of 7 assumes preamble is set to system character-->
<!--only and that transmit check digit is disabled-->
<prop name="UPCELength" value="7"/>
<!--Scanner type, default=0, valid values are: 7 - NixdofrUSB-->
<prop name="ScannerType" value="7"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="ZebraScannerUSB">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra USB" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Other non JavaPOS required properties-->
<!--Comm port device name, must be 'USB' for USB scanner-->
<prop name="port" value="USB"/>
<!--Scanner type, default=0, valid values are: 6 - IBM HID-->
<prop name="ScannerType" value="6"/>
<prop name="ExclusiveClaimLevel" value="1" />
</JposEntry>
<JposEntry logicalName="IBM HANDHELD">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra USB" name="Zebra Scanner" url="https://www.zebra.com" />
<!--Other non JavaPOS required properties-->
<!--Comm port device name, must be 'USB' for USB scanner-->
<prop name="port" value="USB"/>
<!--Scanner type, default=0, valid values are: 6 - IBM HID-->
<prop name="ScannerType" value="6"/>
<prop name="ExclusiveClaimLevel" value="1" />
</JposEntry>
<JposEntry logicalName="ZebraUSBTableTop">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra USB Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Other non JavaPOS required properties-->
<!--Comm port device name, must be 'USB' for USB scanner-->
<prop name="port" value="USBIBMTT"/>
<!--Scanner type, default=0, valid values are: 18944=TableTop(0x4A00)-->
<!--prop name="ScannerType" value="18944"-->
<prop name="ScannerType" value="9"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="ZebraUSBHandHeld">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra USB Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Other non JavaPOS required properties-->
<!--Comm port device name, must be 'USB' for USB scanner-->
<prop name="port" value="USBIBMHID"/>
<!--Scanner type, default=0, valid values are: 19200=HandHeld(0x4B00)-->
<prop name="ScannerType" value="19200"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="ZebraUSBOPOS">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra USB Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Other non JavaPOS required properties-->
<!--Comm port device name, must be 'USB' for USB scanner-->
<prop name="port" value="USBOPOS"/>
<!--Scanner type, default=0, valid values are: 13 -->
<prop name="ScannerType" value="13"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="ZebraScannerSNAPI">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra SNAPI Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Other non JavaPOS required properties-->
<!--Comm port device name, must be 'USB' for USB scanner-->
<prop name="port" value="SNAPI"/>
<!--Scanner type, default=0, valid values are: 2 - SNAPI-->
<prop name="ScannerType" value="2"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="ZebraAllScanners">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra Serial/USB Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Scanner type, default=0, valid values are: 1- ALL Scanners-->
<prop name="ScannerType" value="1"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="IBM HANDHELD">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra Serial/USB Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Scanner type, default=0, valid values are: 1- ALL Scanners-->
<prop name="ScannerType" value="1"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>
<JposEntry logicalName="ZebraScale">
<creation factoryClass="com.motorola.jpos.service.SvcServiceInstanceFactoryImpl" serviceClass="com.motorola.jpos.service.scale.ScaleService113Impl"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scale" version="1.13"/>
<product description="Zebra Scale" name="Zebra Scale" url="https://www.zebra.com"/>
<prop name="ErrorOnSameWeight" value="1"/>
</JposEntry>
The JPOS logical name ‘ZebraAllScanners’ allows scanners on different USB ports to transmit barcodes to a single instance of the spring boot app.
<JposEntry logicalName="ZebraAllScanners">
<creation factoryClass="com.motorola.jpos.service.scanner.SymScannerSvc112Factory" serviceClass="com.motorola.jpos.service.scanner.SymScannerSvc112"/>
<vendor name="Zebra Technologies" url="https://www.zebra.com"/>
<jpos category="Scanner" version="1.12"/>
<product description="Zebra Serial/USB Scanner" name="Zebra Scanner" url="https://www.zebra.com"/>
<!--Scanner type, default=0, valid values are: 1- ALL Scanners-->
<prop name="ScannerType" value="1"/>
<prop name="ExclusiveClaimLevel" value="0" />
</JposEntry>