Specifications

GWY-01-DNT-01 MANUAL – REV. 02 CHAPTER 4:
COMMAND MAPPING
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CHAPTER 4:
COMMAND MAPPING
A command is initiated by a host PC or Programmable Logic Controller (PLC) and is
distributed to the Gateway over a network connection. Once issued, the command is
then executed directly by the Gateway or is otherwise routed to the appropriate RFID
controller (specified by its numerical “Node ID” value, for which there are 16).
In general, there are two types of commands that can be issued:
 Controller Commands - commands intended for one of the attached RFID
controllers. “Read Data” and “Write Data” are two common controller commands.
 Gateway Commands - commands intended for the Gateway itself. Gateway
commands are those commands that query the Gateway for information or
instruct the Gateway to perform a task. The commands “Get Node Status List”
and “Set Notification Mask” are examples of Gateway commands.
4.1 CB X COMMAND PROTOCOL OVERVIEW
In order to execute RFID commands properly, the RFID device and host computer
must be able to communicate using the same language. The language that is used to
communicate is referred to as the Command Protocol. The command protocol used
by GWY-01-DNT-01 is called “CBx.”
The CBx Command Protocol is an advanced protocol that supports Multi-drop
Subnet16 networking with TCP/IP, DeviceNet and Industrial Ethernet applications. It
is based on a double-byte oriented packet structure where commands always contain
a minimum of six data “words” (12 bytes) - even when one or more packet elements
are not applicable to the command.
The CBx packet structures described herein are protocol independent and can be
implemented the same for all protocols (Ethernet/IP, Modbus TCP, DeviceNet, etc.).
ATTENTION: For complete command and response packet structures and examples of
each RFID command, please refer to the CBx Command Protocol – Reference
Manual available at www.ems-rfid.com