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Function Blocks
MBS Modbus Slave Function Block
Revision 11
HC900 Hybrid Control Designer Function Block Reference Guide
199
2/07
Properties Function
Parameter
Index #
Parameter Description
Value or Selection
Modbus
Address
2
Address of Slave device
on the Modbus link
Enter unique address between
1 and 247
Default MB address = 255
which means slave will
NOT
be
in scan
Modbus Double
Register Format
Each IEEE 32-bit floating point number requires two consecutive registers
(four bytes) starting with the register defined as the starting register for the
information. The stuffing order of the bytes into the two registers differs
among Modbus hosts. The selections are:
Selection
Description
Byte order
FP B
Floating Point Big Endian Format
4, 3, 2, 1
FP BB
Floating Point Big Endian with
byte-swapped
3, 4, 1, 2
FP L
Floating Point Little Endian Format 1, 2, 3, 4
FP LB
Floating Point Little Endian with
byte-swapped
2, 1, 4, 3
READ tab
It looks like this graphically.
H
Table 61 describes the parameters and the value or selection.
Table 61 MBS Block Read tab configuration parameters
Properties Function
Parameter
Index #
Parameter Description
Value or Selection
Edit Output Pins
Output Pin
1
Output pin designation
Register request assigned to
RD1, RD2, RD3, or RD4 pin
Use
Register
2 Register
Request
Click on the “Use Register” field
to assign a register to the
Output pin.
Address
(hex)
N/A Register
Address
Type in the address of the
Read register (in Hex) on the
slave device
NOTE: A single configuration
may contain up to 256
enabled registers.