Specifications

Advanced Configuration Features
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31004624 8/2009
Reserved Sizes (PLC to HMI)
The network transmits data to the HMI as output by writing it to the output data table
in the process image. This table is shared with data for all output modules on the
island bus. When the reserved size (PLC to HMI) value is selected, the range of
available data sizes (in words) appears in the window (see the above figure). The
maximum size includes both the data sent to the island modules and the PLC to HMI
data. Therefore, space that you reserve for PLC to HMI data—plus the output data
for the island bus modules—must not exceed the maximum value. For example, if
your output modules consume four words of output data, you can reserve only the
remaining 11 words (out of 15 maximum) of the output data table for the PLC to HMI
data.
Reserving Data Sizes
To transfer data to the PLC from a Modbus HMI you must reserve sizes for that data.
To reserve these data sizes:
Step Action Result
1 In the module editor window, select the
Parameters tab.
2 In the Parameter name column, expand
the Additional Info Store List by clicking
on the plus (+) sign.
The configurable NIM parameters
become visible.
3 Double-click in the Value column next to
the Reserved Size (Words) of HMI to PLC
table.
The value is highlighted.
4 Enter a value that represents the data
size that will be reserved for data sent
from the HMI panel to the PLC.
The value you enter plus the data size of
your island can not exceed the maximum
value. If you accept the default (0), no
space will be reserved in the HMI table in
the process image.
5 Repeat the above steps to select a Value
for the Reserved Size (Words) of PLC to
HMI table row.
6Press OK when you have entered the
desired data sizes.