ProSoft Technology MVI69-DNP - Manual (Page 44)

MVI69-DNP ♦ CompactLogix or MicroLogix Platform Ladder Logic
DNP 3.0 Master/Slave Communication Module
Page 44 of 129 ProSoft Technology, Inc.
November 3, 2008
3.1.3 DNPBackplane Object
The DNPBackplane object stores the variables required for backplane data
transfer between the module and the processor. The structure of the object is
displayed in the following example:
Tag 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
3.1.4 DNPData Object
The DNPData object stores all the data for an MVI69-DNP module. This includes
the data to interface with the DNP slave port (DNP data set) and the DNP master
port (IED data set). Contained within the object is an array for each data type that
can exist for each of the two data sets. The array sizes are set to match the
configuration set for the module. If multiple MVI69-DNP modules are used within
a rack, a copy of this structure may have to be made to permit each module to
have its own database sizes. Ladder logic is required to transfer the data in this
structure between the module and the processor. Each data type has its own set
of unique block identification codes to distinguish the data contained in the read
or write block.
The structure of the object is shown in the following example:
Tag Name Data Type Description
DNP_BI INT[480] Number of DNP BI data words
DNP_BO INT[480] Number of DNP BO data words
DNP_Cntr DINT[240] Number of DNP counter double-words
DNP_AI INT[480] Number of DNP AI data words
DNP_FLTI REAL[240]
DNP_AO INT[480] Number of DNP AO data words
DNP_FLTO REAL[240]
IED_BI INT[480] Number of IED BI data words
IED_BO INT[480] Number of IED BO data words
IED_Cntr DINT[240] Number of IED counter double-wods
IED_AI INT[480] Number of IED AI data words
IED_AO INT[480] Number of IED AO data words