Application tag commands, Field length value – ThingMagic M5e-Compact User Manual
Page 118
Application Tag Commands
118
Command Set
Here is an example response to the example request specified above. The response
contains two tags as specified in the Tag Count field each with its EPC info and requested
tag read metadata: Read Count, AntennaID and Timestamp:
Tag Data Length
1
2 byte
Length, in bits, of the tag data read for
this tag. This value indicates how many
bytes (ceiling[bits/8]), up to 32, will fol-
low.
Example:
if the value is 0x1D (29) then 4
bytes will follow:
29/4 = 3.625 -- ceiling(3.625) = 4.
Tag Data
1
N bytes
Number of bytes of tag data as specified
in
Tag Data Length
EPC Length
2 bytes
Number of bits in EPC including PC and
CRC bits
PC Word
2 bytes
Tag EPC Protocol Control bits
EPC ID
N bytes
Tag EPC.
Tag CRC
2 bytes
Tag EPC CRC
Repeat fields starting at
Read Count
for remaining tags in message as defined by
Tag Count
CRC
2 bytes
Message CRC
1 - Conditionally returned depending on the Metadata Fields specified in the request.
FF
34
29
00
00
00 15
00 02
SO
H
Length
OpCod
e
Status
Metadata
Flags
Read
Options
Tag
Count
22
11
02
50
CE
F6
00
80
31
C1
11
11
22
22
33
33
44
44
55
55
66
66
FB
15
Read
Count
Ant
ID
Timestamp
EPC
Length
PC Word
Tag EPC
Tag CRC
OE
11
04
1D
3D
3C
00
80
30
00
05
00
00
00
00
00
00
00
00
00
23
54
4A
C8
Read
Count
Ant
ID
Timestamp
EPC
Length
PC Word
Tag EPC
Tag CRC
Field
Length
Value