MODBUS TEST 10-9
MON2000
JULY 2010 Use Single Data Type
Note that the requested number of registers
cannot exceed the amount contained by the
selected message block but you can retrieve
a partial block. You cannot cross a message
block boundary.
Also note that in Standard Modbus mode
each register is 16 bits. Therefore, integers
(SHORT) consist of 1 register while floats
(FLOAT) and long integers (LONG) consist of
2 registers.
5. Type the desired repeat count (how many
times WinMB will read or set the specified
registers before ceasing transmission) in the
Repeat data box.
You can repeat the poll from 1 to 9999
times. A Repeat value of “–1” produces an
infinite polling loop that can be terminated
by clicking the button.
10.3.1 Use Single Data Type
Use this function to assign a data type to a
group of registers you will read or edit.
To poll a group of registers with the same user-
defined data type,
1. Follow Steps 1 through 5 in Section 10.3.
2. Click the Use <Type> to decode registers
radio button to choose this option.
3. Use the Data Type pull-down menu to
assign a data type to the selected registers
(see Section 10.3, Steps 3 and 4).
Boolean registers are not
user-defined (for either
SIM_2251 or User_Modbus)
and primarily contain alarm
flags useful for debugging.
To view the contents of
Boolean registers, select the
“1 (Read Coil)” function
code.
Numeric registers for
User_Modbus can be user-
defined (see
Section 5.18.4). To view
the contents of Numeric
registers, select the “3
(Read Regs)” function code.