Tag Programming
43
Writing Initial EPC Code to Blank Matrics EPC0+ Tags
To write the EPC code to blank tags, ID0 singulation must be used.
If ID2 traversal is to be inhibited on subsequent tags, set the traversal inhibit bit in PE0.
Once written, those tags will not singulate using ID2 unless the EPC code is erased and
then rewritten with traversal inhibit cleared.
Once a valid EPC code is written to Page 2, it cannot be overwritten unless the tag is first
erased. Tag write operations using ID0 singulation cannot distinguish if a tag has
previously been singulated.
Each ID0 singulation will use a new random number. To prevent a single tag from
continually being selected for EPC code writing, an error code is returned if the tag
already has a valid EPC code and an overwrite is blocked.
As stated earlier, the mode must be set prior to writing tags. A typical value for the TM0
register is b:0. A typical value for the PE0 register for writing blank tags is
b:12050180
.
This value sets PE0 for the following:
•
Use ID0 singulation with 2 blocks of random bits
•
Retry count set to 5 (set to a 1 speeds up the write process with only 1 retry)
•
Scroll first turned on
•
Autolength EPC enabled (set the right most digits to 04 for a 64 bit and 08 for a 96 bit)
To write the PE0 register, enter the following:
}Cw,d:PE0,b:12050180!
To sense a tag with a valid CRC and an EPC = all 00’s, write
b:1
a
050180
to the PE0
register. The last 4 digits displayed are the CRC. You should attempt to get good read rates
before trying to write to the tags.
Use the “f:2” so you don’t get an e:55 for trying to overwrite a valid EPC (make sure there
is only 1 tag in the field). If you are only writing the EPC code, there is no need to do a
“
te
”, since the write command process with the f:2 always erases the memory
To write a 96-bit EPC code to a blank tag you may need to set the PE0 register to
b:1a050108
, and enter the following:
}Wa,a:2,b:312233445566778899aabbcc,l:c,f:2!
NOTE:
Writing to tags is very sensitive to the following:
–
RF power (Generally need more power to write than to read tags)
–
Tag spacing from the antenna (Need to get enough power coupled into the tag)
–
Orientation of the tags
Summary of Contents for MP9311 Series
Page 1: ...User s Guide MP9311 Low Power UHF Reader Module THE POWER TO CHOOSE...
Page 6: ...MP9311 User s Guide iv...
Page 12: ...MP9311 User s Guide 6...
Page 34: ...MP9311 User s Guide 26...
Page 58: ...MP9311 User s Guide 50...
Page 59: ......
