Hello All,
I would like to ping those implementing LLRP clients and readers to see
how a particular ambiguity in the LLRP Specification has been
interpreted. At issue are the ModeIdentifier in the
UHFC1G2RFModeTableEntry and the ModeIndex in the C1G2RFControl
parameter.
Readers advertise the supported Gen2 modes in a UHFC1G2RFModeTable, and
each entry contains a 32-bit mode identifier. The abstract description
of this field states that ModeIdentifier "... is a Reader defined
identifier that the client may use to set the Gen2 operating
parameters." This seems pretty clear; whatever value placed in this
field by the reader should be returned in the configuration to select
that particular mode.
The problem is that in the configuration parameter that sends this
identifier, C1G2RFControl, the field is called ModeIndex and is
described as "... an index into the UHFC1G2RFModeTable."
So there are two possible interpretations, and there are problems with
each:
Interpretation 1: ModeIndex should equal ModeIdentifier. The problem is
1) the description of ModeIndex does not state as such; and 2) ModeIndex
is 16-bits in the binary specification, and ModeIdentifier is 32-bits.
Interpretation 2: ModeIndex is an index into the mode table. This
renders ModeIdentifier useless and nothing in the Spec indicates whether
this is a 0-based index or a 1-based index. LLRP convention is 1-based.
Based on the definition of ModeIdentifier, I believe interpretation 1 to
be correct.
My belief is that there are two errata in the Spec, the description of
ModeIndex (which should have been called ModeIdentifier), and the binary
size of the field (after all it is identified as an Unsigned Integer and
not an Unsigned Short in the abstract).
How have others interpreted this field?
Thanks,
C
_______________________________
Chris Delaney | Senior Software Engineer
5000 Birch Street, Suite 7100
Newport Beach, CA 92660
[EMAIL PROTECTED]
M: 949.553.0650 x1239 | F: 949.553.0615
www.impinj.com <http://www.impinj.com/>
<<image002.jpg>>
------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________ llrp-toolkit-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/llrp-toolkit-devel
