Honeywell HC900 - Page 209

Function Blocks
MBR Modbus Read Function Block
Revision 11 HC900 Hybrid Control Designer Function Block Reference Guide 195
2/07
Sequence
Number
Parameter
Field
Action Selections Comments
4
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,
the output is converted
to a floating point.
5
Select a function code
for “Float, Unsigned,
Signed, or Bit Packed”
register data type
• Read Holding
Reg – Function
Code 03
• Read Input
Registers –
Function Code
04
Function code 03 or
Function code 04 is
used to read the
contents of input
registers in the slave.
Select a function code
for “Single Bit”
Register data type.
• Read Coil
Status –
Function Code
01
• Read Input
Status –
Function Code
02
Function code 01 is
used to read a slave's
coil's (discrete output's)
ON/OFF status of the
slave device in a binary
data format.
Function code 02 is
used to read a slave's
input's (discrete
input's) ON/OFF status
of the slave device in a
binary data format.
Output is floating point
equivalent (0.0 or 1.0).
NOTE: Refer to the
Communications
manual for the function
codes supported by the
specific device.
6
Select which bit (0-15)
to read when Register
Data Type = Bit Packed
0 to 15
If read as a bit packed
number, you must
select which bit to
mask (0-15).
The output will be the
floating-point
equivalent (0.0 or 1.0)
of the masked bit.
7
You must press [APPLY] to accept the register changes.