Omron V780 Series, User Manual

Page: 155 / 398

7 - 3
7 Modbus/TCP Communications
UHF RFID System V780-series Reader/Writer User’s Manual (Z389)
7-1
Ou
tlin
e
7
7-1
-2 Modbu
s/T
C
P
F
unction
Codes Supporte
d by th
e V780
The Modbus/TCP function codes that are supported by the V780 Reader/Writer are given in the follow-
ing table.
There are two communications systems used by the V780 depending on the function codes that are
used.
The communications system that uses normal commands that are compliant with Modbus/TCP Class 0
is shown below.
Refer to 7-2 Message Formats on page 7-5 for details on the normal commands.
7-1-2 Modbus/TCP Function Codes Supported by the V780
Function code Description
FC03 and FC16
(normal commands)
These function codes comply with Modbus/TCP Class 0.
The basic Modbus/TCP function codes are classified in Class 0.
Class 0 contains the following two functions: Read Multiple Resisters (FC03) and Write
Multiple Registers (FC16).
These are called normal commands in this manual.
FC100
(expanded command)
This function code has a unique format that was defined by OMRON.
This function code is used to reduce command/response exchanges between the host
device and Reader/Writer and give priority to the performance of communications with
the host device.
This is called an expanded command in this manual.
7-1-3 Communications System
Modbus/TCP Communications System (FC03 and FC16)
Host device
(client)
Reader/Writer
(server)
Ethernet Cable
FC03 or FC16
TCP port number: 502
Command
Response
Power Supply Cable
Modbus/TCP communications instructions
Modbus/TCP Unit or other applicable Unit