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Function Blocks
MBS Modbus Slave Function Block
200
HC900 Hybrid Control Designer Function Block Reference Guide
Revision 11
2/07
Properties Function
Parameter
Index #
Parameter Description
Value or Selection
Register
Data Type
N/A
Register data type
From the drop down menu,
select the Register Data Type
•
Float
•
Unsigned 32
•
Signed 32
•
Unsigned 16
•
Signed 16
•
Bit Packed
•
Single Bit
If read as an integer, output is
converted to floating point
equivalent.
Function
Code
N/A
Several standard Modbus
RTU function codes are
supported. These
standard function codes
provide basic support for
IEEE 32-bit floating point
numbers and 16-bit
integer register
representation of
instrument’s process data
Function code
03 – Read
Holding Registers
or
Function code
04 – Read Input
Registers
is used to read the
contents of input registers in the
slave.
Supported Data Types for
Function Codes 03 and 04.
From the drop down menu,
select a function code for
“Float, Unsigned, Signed, or
Bit Packed”
register data type
Function code
01 – Read Coil
Status
is used to read the coil’s
(discrete output’s) ON/OFF
status of the slave device in a
binary data format.
Function code
02 – Read Input
Status
is used to read the
input’s (discrete input’s)
ON/OFF status of the slave
device in a binary data format.
Supported Data Types for
Function Codes 01 and 02.
Select a function code for
“Single Bit”
Register data
type.
NOTE: Refer to the
Communications manual for the
function codes supported by the
specific device.
Select
Bit
23-26
Bit to read when Read
register’s data type = Bit
Packed
0-15