KW2D Series Smart RFID Reader User’s Manual
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This chapter describes the communication function between the KW2D Smart RFID Reader and the host device or KW
RFID Configurator.
1.1 Communication Specifications
1.2 Communication data format
■
Transaction ID
The ModbusTCP Server returns the transaction ID from the client as is. The client can see which transaction the server
is responding to. Set it to 0 if you do not want to check.
■
Protocol ID
The ModbusTCP protocol is identified by the value 0.
■
Message Length
Indicates the size of the Unit ID and data fields in bytes.
■
Unit ID
An ID for identifying the device. Stores the slave number of the ModbusTCP Server. The ModbusTCP Server of the
KW2D Smart RFID Reader accepts and processes requests regardless of the Unit ID of the received request.
Chapter 4
Communication Function
1
ModbusTCP Communication (Server)
Item
Specifications
Supported protocol
ModbusTCP Server
Maximum number of
simultaneous clients
1 client per port
Port No.
502, 503, and 504
Unit ID (station number)
Unused (If a station number must be specified on the ModbusTCP client side, specify 1.)
Access control
1 IP address can be specified per port. (Set in KW RFID Configurator)
Supported function codes
01: Read the value of coil relay (000001 to 000016)
02: Read
the value o
f input relay (100001 to 100032)
03: Read the value of holding register (400001 to 400032)
04: Read the value of input register (300001 to 300032)
05: Write a value to a coil relay (000001 to 000016)
06: Write a value to a holding register (400001 to 400032)
15: Write values to multiple coil relays (000001 to 000016)
16: Write values to multiple holding registers (400001 to 400032)
Function
• Read tag information
• Read status information
• Control LEDs and buzzer
Transaction ID
Protocol ID
Message Length
Unit ID
Data fields
Function code
Contents
1 byte
2 byte
2 byte
2 byte
1 byte
N byte
