Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
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Chapter 6 Micro870 Controller Distributed Network Protocol
Max Random Delay (x1 ms)
This parameter is used with Pre-transmit Delay (x1 ms) for Collision Avoidance on RS-485
network. For more details, see
Collision Avoidance on page 112
The valid range is 0…65535. Default value is 0.
Ethernet Layer Configuration Parameters
The DNP3 over IP subsystem in the controller supports Listening End Point, TCP Dual End Point
and Datagram End Point type.
Listening End Point type supports a single TCP connection as a Server and UDP datagram.
TCP Dual End Point type supports a single TCP connection as a Server, a single TCP connection
as a Client and UDP datagram.
Datagram End Point type supports UDP datagram from DNP3 Masters. The default TCP and UDP
port numbers are 20000 and the port numbers are configurable.
The End Point type can be determined by the parameter End Point Type. According to the
parameter, the controller works as different End Point types. See
configuration.
The parameter DNP3 over IP Enable is configured in the Ethernet configuration page and other
parameters are configured in the DNP3 Slave configuration page.
Table 6 - End Point Types
End Point Type
Connection
Description
Listening End Point
A single TCP server connection
Any of the requests are accepted and the responses
are transmitted via this connection.
The unsolicited responses are transmitted via this
connection when this connection is available.
UDP datagram
Accepts only broadcast packets when DNP3
destination node is one of 0xFFFD, 0xFFFE and
0xFFFF in the request.
Dual End Point
A single TCP server connection
Any of the requests are accepted and the responses
are transmitted via this connection.
The unsolicited responses are transmitted via this
connection when this connection is available.
This connection has higher priority than the Client
connection.
A single TCP client connection
Any of the requests are accepted and the responses
are transmitted via this connection.
The unsolicited responses are transmitted via this
connection when this connection is available.
The controller does not request TCP client connection
to DNP3 Master until an unsolicited response is
generated.
UDP datagram
Accepts only broadcast packets when DNP3
destination node is one of 0xFFFD, 0xFFFE and
0xFFFF in the request.
Datagram End Point
UDP datagram only
Any of the requests are accepted and the responses
are transmitted via this connection.
All responses can be transmitted to the different
DNP3 Master port according to the configuration of
the parameters Remote UDP Port Number and Master
IP Address0. If this parameter is not set to 0, the
solicited responses are sent to the DNP3 Master port
that is configured. If this parameter is set to 0, the
solicited responses are sent to the DNP3 Master port
that sent the request.
TCP connection is not available in this configuration.