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)