Why Should a Length be Set When Scanning MSI Plessey?

Article ID: 27374362


Why is the scanner mis-decoding MSI Plessy bar codes?


Motorola/Symbol scanner


Motorola/Symbol scanner has been programmed to read MSI Plessey bar codes of any length.  This is causing mis-decodes and partial data to be sent to the host.

Unlike most symbologies, start and stop characters in MSI Plessey are not reserved.  If the scanner were to pick up a partial scan of the bar code, it is possible that part of the code will be transmitted.

When configuring the Symbol scanner to read MSI Plessey, a length should be specified. One Discrete Length, Two Discrete Lengths, or Lengths within a Range, are the available choices for MSI Plessey. Configuring the scanner for one of these length options will prevent partial scans from being read.

Bar codes are located in the Product Reference Guide that corresponds to the scanner model you wish to program.   Product Reference Guides can be found at Motorola Solutions Support. 

1.     Enable MSI Plessey Any Length.

2.     Scan your MSI Plessey bar code(s). This will show you how many characters are in your code(s).

3.     To enable the scanner to read one discrete length, you will need to scan the “MSI Plessey One Discrete Length” bar code, followed by the two digit length.  For example, if the bar code length is 2 characters, you would scan MSI Plessey One Discrete Length from the Symbology section of the appropriate PRG then scan 0, then 2 from the Numeric section of the PRG.  If it is 10 characters long, you would scan 1, then 0.

4.     Choosing MSI Plessey Two Discrete lengths will allow only the two lengths selected to be scanned.  For two discrete lengths, you would scan the “MSI Plessey Two Discrete Lengths” bar code, followed by the four digits representing the first and second lengths.   For example if you are going to be scanning bar codes that are two and 10 characters long, then you would scan MSI Plessey Two Discrete Lengths, 0, 2, 1, 0.

5.     Setting a Length within Range will only allow decoding of bar codes whose code length meets or is between the criteria set by the lower and upper values.  If the range is set for 2 to 10 characters, then you would be able to scan any length between two and ten characters inclusive.  To program the scanner to read a length within range, scan “MSI Plessey Length within Range”, followed by the four digits representing the range.  For Example a range of 2 to 14 characters would be scanned as MSI Plessey Length within Range, 0, 2, 1, 4.