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SMD23E2 and SMD24E2 User’s Manual
M
ODBUS
TCP C
ONFIGURATION
121
6.5 Supported Modbus Functions
Table T6.1 Supported Modbus Functions
Table T6.1 above lists all of the Modbus functions supported by an SMD23E2 or SMD24E2. AMCI supports
all of these functions so that you can control the unit as you see fit. However, if you are looking for the easiest
way to interface with your unit, then you only need to use the
Read/Write Registers
function, which is func-
tion code 23.
Each SMD23E2 or SMD24E2 buffers the data that is sent to it over the network. If you use the
Read/Write Registers
function to write configuration data to the unit, then the data read with
that command will not contain the response to the new configuration data. The response to the
new data will be sent with the next data read.
6.6 Supported Modbus Exceptions
Table T6.2 Supported Modbus Exceptions
Function
Code
Function Name
SMD23E2 or SMD24E2
Register
Addressing method
1
Read Coils
OUTPUT
Bit: Addresses starting at 16,384
2
Read Discrete Inputs
INPUT
Bit: Addresses starting at 0
3
Read Holding Registers
OUTPUT & INPUT
Word: Out Regs. Starting at 1024
In Regs.
Starting at 0
4
Read Input Registers
INPUT
Word: Addresses starting at 0.
5
Write Single Coil
OUTPUT
Bit: Addresses starting at 16,384
6
Write Single Register
OUTPUT
Word: Addresses starting at 1024
15
Write Multiple Coils
OUTPUT
Bit: Addresses starting at 16,384
16
Write Multiple Registers
OUTPUT
Word: Addresses starting at 1024
22
Mask Write Register
OUTPUT
Word: Addresses starting at 1024
23
Read/Write Registers
INPUT/OUTPUT
Word: Out Regs. Starting at 1024
In Regs.
Starting at 0
Code
Name
Description
01
Illegal function
The SMD23E2 or SMD24E2 does not support the function code in the query.
02
Illegal data address
The data address received in the query is outside the initialized memory area.
03
Illegal data value
The data in the request is illegal.
