ProSoft Technology MVI69-HART - Manual (Page 51)

MVI69-HART ♦ CompactLogix Platform Ladder Logic
HART Multi-drop Master Communication Module User Manual
ProSoft Technology, Inc. Page 51 of 169
March 29, 2012
Backplane Object (HARTBackplane)
The HARTBackplane object stores all the variables required for the data transfer
operation between the module and the controller. The LastRead data member is
used as the handshaking byte to indicate the arrival of new data from the
module. The following table describes the structure of the object.
Name Data Type Description
LastRead INT Index of last read block
LastWrite INT Index of last write block
BlockIndex INT Computed block offset for data table
The other members of the object are be used in the ladder logic to assist in the
data transfer operation.
3.1.3 Data Object (HARTData)
The HARTData object is defined in the example ladder logic to demonstrate how
the data from a module can be stored in the processor. This object can be used
to temporarily store a received data set. In this example, four data areas are set
up; two for input data (data received from the module) and two for output data
(data to transfer to the module). Within each of these two areas, an area for
floating-point data and integer data is defined. The following table describes the
structure of the object.
Name Data Type Description
HART_IN_Float_vals REAL[100] Data area to floating-point data
HART_IN_Int_vals INT[500] Data area to hold integer data
HART_OUT_Float_vals REAL[100] Data area for output floating-point data
HART_OUT_Int_vals INT[500] Data area for output integer data