IO754 - Message v2
IO754 - Message v2 — Receives/Transmits cyclic data
from/to the Modbus TCP network
Library
Simulink Real-Time - Speedgoat
Description
This block processes the function code requests from a client and writes/reads the
Modbus data to/from the different areas (coils, discrete inputs, holding registers
and input registers).
You model can contain multiple Modbus TCP Server Message blocks for each I/O
module in your target machine.
Message blocks can only be used in Message mode. Select this mode in the related
Setup block.
Ports
The block has either one input port or one output port depending on the selected
function (write/read).
Coils and Discrete Inputs:
Both input and output ports are a vector of the Boolean data type where
the length of the value is defined by the Quantity parameter. Each BOOLEAN
element of the vector represents one bit.
Holding Registers and Input Registers:
Both input and output ports are a vector of the UINT16 data type where the
length of the value is defined by the Quantity parameter.
Parameters
-
Module ID
This ID defines the link to the corresponding Setup block.
-
Sample Time
Defines the base sample time at which this driver block gets its sample hit. This
parameter can also be set to -1 for inherited
sample time. The units are in seconds.
![[Caution]](images/caution.png) | Caution |
|---|
All blocks that interface with the same I/O module must have identical
sample times. |
-
Command
Write or read data to one of the different Modbus data areas (coils,
discrete inputs, holding registers and input registers).
-
Address
Options for different data tables:
Coils and discrete inputs: For these bit-based values, the
parameter defines the start bit.
Holding registers and input registers: For these
WORD-based values, the value defines the register start
address.
-
Quantity
Options for different data tables:
Coils and discrete inputs: Defines the number of bits that
should be written to the Modbus buffer or that should be
read from the buffer
Holding registers and input registers: Defines the number
of registers that should be written to the Modbus buffer or
that should be read from the buffer
-
Initial Values
Define values the block outputs until data is initially received from
the client. The length of the vector must match Quantity. Enter an empty array if you do not want to
specify initial values. This parameter only applies to the Read Coils
and Read Holding Registers commands. In all other cases the parameter is
hidden.