ProSoft Technology MVI69-DNPSNET - Manual (Page 39)

Ladder Logic MVI69-DNPSNET ♦ CompactLogix or MicroLogix Platform
Distributed Network Protocol Interface Module
ProSoft Technology, Inc. Page 39 of 119
November 3, 2008
Name Data Type Description
UDP_ST_Value INT UDP Socket State Value
Busywithmsg INT DNP Busy with Message State
App_Fragm INT Application fragment
Tx_frame_ST INT Transmit frame State
TCP_msg_len INT TCP message length
UDP_msg_len INT UDP message length
Port_Tx_St INT Port Transmit state
Free_Mem DINT Free Memory
This information is important as it can be used to view the "health" of the module.
If the module is not communicating, examine the object to help find the problem.
Additionally, you should use the configuration/debug port on the module to
confirm that the desired configuration of the module is implemented.
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:
Name Data Type Description
BlockTransferSize INT
LastRead INT Index of last read block
LastWrite INT Index of last write block
BlockIndex INT Computed block offset for data table
ReadData INT[240] Buffer File for data Read from Module
WriteData INT[240] Buffer File for data Write from Module.
3.1.2 DNPData Object
The DNPData object stores all the data for an MVI69-DNPSNET module.
Contained within the object is an array for each data type. The array sizes are set
to match the configuration set for the module. If multiple MVI69-DNPSNET
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. The
structure of the object is shown in the following example:
Name Data Type Description
DNP_BI INT[20] Number of DNP BI data words
DNP_AI INT[40] Number of DNP AI data words
DNP_FLTI REAL[20] Number of DNP Float Input Points
DNP_Cntr DINT[10] Number of DNP counter double-words
DNP_BO INT[40] Number of DNP BO data words
DNP_AO INT[40] Number of DNP AO data words
DNP_FLTO REAL[20] Number of DNP Float Output points