Comtrol UP DeviceMaster Filtering and Data Extraction - Manual (Page 11)

Chapter 3. RFID Data Extraction and PLC/Application InterfaceDeviceMaster UP Filtering and Data Extraction Reference Guide: 2000470 Rev. B - 11
Chapter 3. RFID Data Extraction and PLC/
Application Interface
The RFID data extraction process extracts the various parameters from EPCglobal formatted tags. It is
designed to greatly simplify PLC and application programming tasks.
EPCglobal is the world wide standard for RFID tag formats. It encompasses a number of 64 and 96 bit
encoding schemes and, at present, a total of 43 specified formats, of which 35 are unique.
When RFID filtering is enabled and a valid filtering criteria is specified, all received data is sent to the PLC
and/or application in a consistent format. If a tag with a valid EPCglobal format is received, the various
parameters will be extracted and placed into a formatted data message. The associated tag ASCII string will
be placed in the message data area. (The ASCII tag format may vary depending on the RFID reader.) Any
non-tag messages will be placed in the data area and the tag parameters will be set to zero.
3.1. RFID Data Formats
The RFID data formats have the following characteristics:
• For the PLC, contains the same Produced Sequence Number and Length fields as a regular receive data
message.
• Contains the RFID specific parameters and the RFID tag ASCII string (or unknown message data).
• Has a similar format for both the PLC and application interface.
3.1.1. PLC RFID Data Format
When the PLC interface is operating in RFID filtering mode, all data sent to the PLC uses this format.
Fields Data Type Description
Produced data
sequence number UINT
Values = 0-65535 (FFFF Hex)
Sequence number that is incremented with each new
message.
Length of RFID
message UINT
Values = 20-148
Length in bytes of following data.
Company Code UDINT[2]
Company Code extracted from tag data. Depending on
encoding scheme, this field may include Company
Prefixes, Company Prefix Indexes, or Government
Managed Identifier.
Product/Location
Code
UDINT[2]
Product Code extracted from tag data. Depending on
encoding scheme, this field may include the Item
reference, location reference, asset reference, object class,
or be set to zero.
Serial Number UDINT[2]
Serial Number extracted from tag data. Depending on
the encoding scheme, this field may include the Serial
Number or individual asset reference.
Encoding Scheme UINT Encoding scheme from tag data.
Filtering Value UINT Filtering value from tag data.
Antenna Number UINT Antenna number on RFID reader/scanner.
Tag Data Length UINT Length of RFID tag string in bytes.