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Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Chapter 6 Micro870 Controller Distributed Network Protocol
DNP3 Slave Application
Layer
This section covers DNP3 Slave Application Layer Function Codes and Internal Indications. All
of the Function Codes that are supported in the controller are summarized in
for DNP3 in Micro870 Controllers on page 116
For details of Packet Formats for the request and response, see the DNP3 Protocol
specifications.
Function Codes
CONFIRM (FC Byte = 0x00)
00 – Confirm
A DNP3 master sends a message with this function code to confirm receipt of a response
fragment. In a general environment, the controller receives a response with this function code.
But the controller may generate a response with this function code when a DNP3 Master sends
a request with the CON bit set in the application control header.
READ (FC Byte = 0x01)
01 – Read
The READ function code is used by a DNP3 master to request data from the controller.
WRITE (FC Byte = 0x02)
02 – Write
The WRITE function code is used to write the contents of DNP3 objects from the DNP3 master
to the controller. This function code is used for clearing bit IIN1.7 [DEVICE_RESTART], setting
time in the controller and downloading user programs to the controller.
SELECT (FC Byte = 0x03)
03 – Select
The SELECT function code is used in conjunction with the OPERATE function code as part of
select-before-operate method for issuing control requests. This procedure is used for
controlling binary output (CROB) or analog output (AOB) objects.
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16-bit Analog Output Command Change Object
2 - 16-bit without time
0 - All variation
1 - 32-bit without time
3 - 32-bit with time
4 - 16-bit with time
5 - Single-precision, floating-point without time
6 - Double-precision, floating-point without time
7 - Single-precision, floating-point with time
8 - Double-precision, floating-point with time
32-bit Analog Output Command Change Object
1 - 32-bit without time
0 - All variation
2 - 16-bit without time
3 - 32-bit with time
4 - 16-bit with time
5 - Single-precision, floating-point without time
6 - Double-precision, floating-point without time
7 - Single-precision, floating-point with time
8 - Double-precision, floating-point with time
Short Float Analog Output Command Change Object
5 - Single-precision, floating-point without time
0 - All variation
1 - 32-bit without time
2 - 16-bit without time
3 - 32-bit with time
4 - 16-bit with time
6 - Double-precision, floating-point without time
7 - Single-precision, floating-point with time
8 - Double-precision, floating-point with time
Table 7 - DNP3 Default Variation Configuration File (Continued)
Group Default Variation for the following Objects
Standard Default Variation
Alternate Default Variations