TransCore MPRX, System Manual

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User Guide
TransCore Proprietary 7–34
697 Set User-Programmable Group Select Equals (GSE) Filter
Command #697 sets the user-programmable GSE filter.
The command string is assigned according to the following format:
697 MM AA DDDDDDDDDDDDDDDD
where
MM = The tag uses this mask to determine which of the eight Comparison Data bytes are to
be compared for the Group Select filter.
AA = This field is used by the tag to determine the start address in the tag memory for the
comparison data.
DD…DD = Comparison Data: an 8-byte field (16 characters) used by the tag as the
comparison data for the Group Select filter. The tag compares the data in this field to data
in tag memory beginning at the Start Address to determine if the tag will respond to a reader
Group Select request. Only the bytes having the corresponding bit set in the GSE Mask is
used for this comparison.
As an example, to configure a reader to have only tags with data in byte locations 10, 12,
and 15 (decimal) with hexadecimal values “00,” “01,” and “02,” the following command is
used:
#697 A4 0A 0005014202024133
To understand how the data is interpreted, it is necessary to break down the GSE Mask field,
A4, into binary:
A4 =
1010 0100
This mask equates to the tag comparing the first, third, and sixth bytes of the Comparison
Data to data in the tag beginning at address location 0A (10 decimal).
The Comparison Data field is broken down in bytes with the bytes corresponding to the
mask underlined in bold (for clarification):
Address:
0A 0B 0C 0D 0E 0F 10 1
1
Data:
00 05 01 42 02 02 41 33
where
0A (10 decimal) must be equal to “00” hexadecimal, the first byte in the Comparison Data
field
0C (12 decimal) must be equal to “01” hexadecimal, the third byte in the Comparison Data
field
0F (15 decimal) must be equal to “02” hexadecimal, the sixth byte in the Comparison Data
field
Reader response:
Done