Rockwell Automation 1758-RTU202 DataSite Software User Manual FRN 1.2 - Manual (Page 237)

Publication 1758-UM002D-EN-P - October 2010
DataSite DNP3 Configuration Utility (DS DNP3) 237
SDNP3 SDNP3 is a simplified protocol based on DNP3.
The maximum number of data points that can be configured is 400. The
maximum size of each session that can be configured is 200 data points.
Class 0 is static data without event characteristics. Classes 1, 2, and 3 contain
event characteristics. In each session, the buffer for AI, DI, PI, Freeze PI
events can be set to a maximum length of 2000 data points, and String event
buffers can be set to a maximum of 10 data points.
When the event log exceeds the set value, the oldest record will be overwritten
with the newest record. For example, if the AI value threshold is set as 100,
when the AI value exceeds 100, the event will be recorded into one data point.
Since only inputs have active reporting, only input objects have event buffer.
For example, AI, DI, PI, Freeze PI and String. Output objects, such as AO and
DO, have no event buffer.
Every data point has a corresponding data type. For example, the data type for
DO and DI is Bool. AI and DO have three data types, namely 16-bit, 32-bit,
and Float. PI has two data types, namely 16-bit and 32-bit. String has four data
types, namely String(20), String(60), String(100), and String(250).
The range of values for each data type is listed in the following table.
SDNP3 Network Structure
When using the SDNP3 communication protocol with the support of
different communication channels, different communication structures can be
set up, such as point-to-point, point-to-multipoint, multipoint-to-multipoint.
Data types and value ranges
Data Type Range of Values
Bool 0 or 1
16-bit 0…65535
32-bit -2147483648…2147483647
Float -3.4*10^38…3.4*10^38
String(20) 20 bytes
String(60) 60 bytes
String(100) 100 bytes
String(250) 250 bytes