User Manual

CHAPTER 7: RFID COMMANDS
COBALT HF RFID CONTROLLERS OPERATOR’S MANUAL
P/N: 17-1320 REV 01 (03-06) PAGE 88 OF 116
Command 0D instructs the controller to start (or stop) Continuous Read Mode.
When the Cobalt Controller is in Continuous Read Mode, it will constantly emit RF energy
in an attempt to read any tag that comes into range of the antenna. As a tag enters the
antenna field, it is immediately read and the data is passed to the host. The controller will
continue to read the tag but will not re-send the same data to the host until the tag has
moved outside the RF field for a specified time period. This parameter is known as the
Delay Between Duplicate Reads
, which prevents redundant data transmissions when the
controller is in Continuous Read Mode.
If another RFID command is executed while the controller is in Continuous Read Mode,
the Cobalt HF will temporarily stop Continuous Reading to execute the command, after
which the controller will return to Continuous Read Mode.
The Start/Stop Continuous Read command contains three primary components: a Start
Address, a Read Length and a Delay Between Duplicate Reads value.
x Start Address: The Start Address is a 2-byte integer indicating the tag address
location where the read will begin.
x Read Length: The Read Length is a 2-byte integer that represents the number
of tag data bytes of retrieve. By setting this parameter to one (0x01) or higher,
Continuous Read Mode will be switched ON at the completion of the command.
Setting the Read Length to zero (0x00) will turn Continuous Read Mode off.
x Delay Between Duplicate Reads: During Continuous Read Mode, any tag that
comes within range of the antenna will be constantly read and the requested data
from the tag will be passed to the host. This single-byte delay parameter
indicates the number of seconds that a tag must remain out of RF range before it
can be re-read and have its data sent to the host for a second time. It is
implemented to enable the operator to limit the volume of information sent by the
controller. The Delay Between Duplicate Reads parameter can have a value of 0
to 60 seconds. When the Delay Between Duplicate Reads value is set to 0, the
controller will continuously read AND transmit duplicate tag data to the host.
Continuous Read at Power-up
By default, Continuous Read Mode is not restarted if the controller is reset. However,
through the use of the RFID Dashboard Utility, the Cobalt Controller can be configured
to enter Continuous Read Mode automatically after a reset or power-up. See Section 3.1
for more information regarding the RFID Dashboard Utility or visit:
www.ems-rfid.com
.
COMMAND 0D:
START/STOP CONTINUOUS READ