Rockwell Automation Publication 2080-UM002M-EN-E - April 2022 81
Chapter 6 Micro870 Controller Distributed Network Protocol
Message Retries
When Confirmation Timeout (x1 ms) has expired and this parameter was non-
zero value, the controller tries to send retry packets.
The valid range is 0…255. Default value is 0.
Pre-transmit Delay (x1 ms)
The controller waits for the specified time before sending the packet.
The valid range is 0…65535. Default value is 0.
RTS Off Delay (x1 ms)
When the Control is set at Half Duplex Modem (CTS/RTS handshaking), this
feature is enabled. This specifies a time delay between the end of a
transmission and dropping of the RTS signal.
The valid range is 0…65535. Default value is 0.
RTS Send Delay (x1 ms)
When the Control is set at Half Duplex Modem (CTS/RTS handshaking), this
entry is enabled. This specifies a time delay between the raising of the RTS and
the initiation of a transmission.
The valid range is 0…65535. Default value is 0.
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 122.
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.