Outline Of Modbus Tcp And Transmission Format; Connections (When Set To Modbus Tcp); Compare Packet Of Modbus Tcp And Modbus (Rtu And Ascii) - Panasonic KS1 User Manual

6-5 Outline of MODBUS TCP and Transmission format

6-5-1 Connections (When set to MODBUS TCP)

PC etc.
Ethernet
→①command
MODBUS
←④response
TCP
Client
・MODBUS TCP server (KS1 Signal converter) is connected from MODBUS TCP client.
・MODBUS TCP server is designated by specific IP address and port number.
・ MODBUS TCP server (KS1 Signal converter) converts data from MODBUS TCP client
(command) to MODBUS RTU or MODBUS ASCII and send from the serial port. After that, it
converts data from the serial port (response) and send to MODBUS TCP client.

6-5-2 Compare Packet of MODBUS TCP and MODBUS (RTU and ASCII)

①Example of Command data from MODBUS TCP client to MODBUS TCP server
Item
Ex. of setting value 0001
Meaning
Setting range
This shows the command to read out 1 byte data designated by 238D send from MODBUS
TCP client to serial communication device number 01.
②Example of MODBUS RTU Command from MODBUS TCP server (KS1 Signal converter) to Serial
slave unit
Item
Ex. of setting value 0103238D0001
Meaning
Setting range
・This shows the command to read out data designated by 238D send from MODBUS TCP
server (KS1 Signal converter) to serial communication device number 01.
・Pick up transmit data from MODBUS TCP client, and when it is MODBUS RTU, it send
command with additional CRC, and when it is MODBUS ASCII, it send command with
additional LRC.
③Example of MODBUS RTU response from serial communication device to MODBUS TCP server
(KS1 Signal converter)
Item
Ex. of setting value 0103020128
Meaning
Setting range
・This shows the response to send 2 bytes data 0128(Hex) designated 238D send from serial
communication device number 01 to MODBUS TCP server (KS1 Signal converter).
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
KS1 Signal converter
MODBUS TCP server
convert
Serial port
Transmit ID Protocol ID
0000
ID of Fixed
Transmit unit value
00 to FF Fix to 0000
Data
Slave unit No. 01
Function code 03
Data address 238D
Data 1 byte
Any value
Data
Slave unit No. 01
Function code 03
Data 2 byte
Data value 0128 (Hex)
・RS232C
→②command
←③response
・RS485
Transmit byte
0006
Number of byte
of transmit data
Any value
21
Serial communication
device
Slave
Transmit data
0103238D0001
Slave unit No.01
Function code 03
Data address 238D
Data 1 byte
Any value
CRC
1FA5
CRC value of data
Calculated value 2 bytes
CRC
B9CA
CRC value of data
Calculated value 2 bytes