ProSoft Technology MVI69-DNPSNET - Manual (Page 86)

MVI69-DNPSNET ♦ CompactLogix or MicroLogix Platform Reference
Distributed Network Protocol Interface Module
Page 86 of 119 ProSoft Technology, Inc.
November 3, 2008
DNP Counter Data
This data type stores accumulated count data. These data are stored in the
module in a double word value and have a data range of 0 to 4,294,967,296. The
size of this data area is determined from the configuration parameter Counters.
The PLC transfers data of this type to the module using the read operation. The
module maintains two values for each counter point: a current running value and
a frozen value. The DNP master must send the freeze command to the module in
order to transfer the current running values to the frozen area.
Note: The freeze-reset command is not supported in the data transfer operation. There is no way
to guarantee counts will not be lost using the freeze-reset operation, therefore, this feature is not
implemented.
A data flow diagram for the counter data is shown in the following figure.