
MANUEL STA46
Modbus TCP
JP Viskovic 30/08/2005 OEE-F
4
1. Specifications
1-1
Supported command list
Code
(Hex)
Function
Name in MODBUS
0x01
I/O memory area (CIO) Read Multiple Coils
Read Coils
0x02
I/O memory area (CIO) Read Multiple Coils
Read Discrete Inputs
0x03
I/O memory area (DM) Read Multiple Registers
Read Holding Registers
0x04
I/O memory area (CIO) Read Multiple Registers
Read Input Registers
0x05
I/O memory area Write Single Coil
Write Single Coil
0x06
I/O memory area (DM) Write Single Register
Write Single Register
0x08
Echo back test
Diagnostic
0x0F
***** NOT SUPPORTED ******
Write Multiple Coils
0x10
I/O memory area (DM) Write Multiple Registers
Write Multiple Registers
1-2 Memory
map
1-2-0
Used by ModbusTCP PLC program
Modbus process
Type
Memory address
Descriptions
Work Area
W480 -511
Used for counter and calculation
Receive Area
CIO 5800 - 6000
Used to store received bytes
Send Area
CIO 6001 - 6143
Used to prepare bytes to send
Ethernet Unit flag & command switch (Unit n°0)
Type
Memory address
Descriptions
Flag/command Area
CIO1000- CIO1024
Parameter Area
D 30000 - D30099
For more details see Op. manual W343
1-2-1
PLC area accessible by Modbus TCP request
MODBUS
Address
PDU
Address
Corresponding CS/CJ’s address
Discrete Inputs
1 - 5120
0 - 5119
0 – 5119 (CIO 0.00 - CIO319.15)
Coils
1 - 65536
0 - 65535
0 – 65535 (CIO 0.00 – CIO4095.15)
Input Registers
1 - 5801
0 - 57800
0 – 5800 (CIO0 – CIO5800) *
Holding Registers
1 - 32768
0 - 32767
0 - 32767 (D0 – D32767)
*: area 5801 to 6143 is reserved for the ModbusTCP PLC program (see 1-2-0)