ProSoft Technology MVI71-DNP - Manual (Page 100)

MVI71-DNP ♦ PLC Platform Reference
DNP 3.0 Master/Slave Communication Module
Page 100 of 172 ProSoft Technology, Inc.
August 23, 2007
The following illustration shows the relationship between the PLC5 data files and
the DNP and IED memory areas in the module. Note that each data type is
allocated its own PLC file. This limits the number of data points that can be
defined for each data type to the maximum size of a PLC5 data file.
Block Data Transfer Interface
Data can be transferred between the PLC and the module using BTR and BTW
operations. Each block transfer operation transfers 64 words of information of
which 60 holds data. The other four words in the block contain block header
identification codes or are not used. The module defines the blocks to be
transferred between the PLC and the module when the system is initialized.
The block transfer numbers are fixed in the program for each data type for your
specific application. Block numbers are assigned by the application based on the
number of points of each type. The application only allocates the number of
blocks required to hold the data point count specified. For example, if 200 digital
input points are required for the application, only block 0 is allocated. If 50
counter points are required, blocks 40 and 41 are defined.
The following table shows the block identification numbers used for data transfer.
Data Type Start Block # Max Block # Max # Of Points
Digital Input 0 15 15360
Digital Output 20 35 15360
Counters 40 55 480
Analog Input 60 75 960
Analog Output 80 95 960
IED Digital Input 1000 1015 15360
IED Digital Output 1020 1035 15360
IED Counters 1040 1055 480
IED Analog Input 1060 1075 960
IED Analog Output 1080 1095 960
Float Input 1100 1107 240
Float Output 1140 1147 240