Emerson DL8000, Instruction Manual

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DL8000 Preset Instruction Manual
Revised February-2016 Modbus Communications B-15
Field Description
Start Register Indicates the first data register in the address span.
Valid values are 0 to 65535 . You can duplicate
register numbers as long as you assign them to
separate (unique) communication ports. Number
tables from smallest to largest.
Note : Certain Modbus host devices transmit the
register 40101 as 100 . In those cases, place
100 in this field, since the DL8000 uses the
actual host-send value.
For example, a host device requests start register
500 through end register 700. You define the start
register as 400 and the end register as 700. All the
registers the host requests (500 through 700) are
valid and would be answered because the requested
register number match or fall between the defined
start and end register numbers (400 and 700,
respectively).
End Register Indicates the last data register in the address span.
Determine this value by adding the total number of
defined registers to the number of the start register
and then subtracting one. For example, if you define
a total of 120 registers and the first data register is 6,
the value for this field is 125 (120+6-1=125).
Device
Parameter(s)
Indicates the type of data associated with an address
(composed of the start register through the end
register). Click the field to display the TLP button (
…
)
to set parameters.
Indexing Indicates the type of indexing. Valid values are Point
or Parameter . The default is Point .
Point Start register is mapped to the
selected device parameter.
Subsequent registers (through the
end register) are mapped to the
same point type and parameter and
increment the Logical number.
Parameter Start register is mapped to the
selected device parameter.
Subsequent registers (through the
end register) are mapped to the
same point type and point logical
number, and increment the
Parameter number.
Note : Indexing allows you to define a block of
register values as successive logical point
numbers or parameters without defining each
register value separately.