RFID Communications
LRP2000 Passive Reader/Writer 58
At the pallet level, a read command of the case level family coded tags would produce the quantity of
cases on the pallet and the case data and the quantity of cases could be written to the pallet tag using the
pallet tag family code. This way a pallet going through a gate can be read quickly by just reading the pallet
family codes and ignoring the case and item level family coded tags. Or if quantity verification is required, a
more time consuming read of case level or even item level can be issued.
The multi-tag commands always have a Family Code as a parameter. The Family Code is a one-byte field
in the tag, which resides outside the read/write memory address space. When the Family Code parameter
is set to 0, all the tags in the field will respond. When the Family Code parameter is set to a non-zero byte
value, only tags with the same specified Family code will respond. The Family Code byte can be read,
written, and locked independently of the rest of the read/write address space in the tag.
6.3.3 Start Continuous Read
This parameter, included only on command 83H, is a one-byte parameter that starts the Continuous Read
if set to 01H, and stops the Continuous Read if set to 00H. Both of the other Continuous Read
commands— 0DH and 8DH—rely on the Number of Bytes to be read to start and stop the command. If the
Number of Bytes is set to any valid nonzero value, the Continuous Read starts. If it is set to zero, the
Continuous Read stops. The use of this additional parameter on command 83H allows for the Number of
Bytes to be set to zero upon initiation of the command, thereby interrogating the tags only for their serial
numbers.
CAUTION:EMS recommends that before issuing other commands, you always issue a Stop Continuous
Read command, and then issue a Start Continuous Read after the interim command has been
executed. Applications that send other commands during Continuous Read mode should be
thoroughly tested before deployment.