ABB 620 Series Manual page 26

Section 4
DNP3 parameters
20
Application layer parameters
App layer confirm When disabled, the IED requests application confirmation to event
messages only. When enabled, the IED also requests application confirmations to all
application messages sent.
App confirm TO is the application layer confirmation timeout in milliseconds. Application
layer confirmations received from the master after App confirm TO has expired are not
acknowledged by the IED. It applies to both solicited and unsolicited events.
App layer fragment is the application layer fragment size in bytes.
Unsolicited mode parameters
UR mode Unsolicited responses mode may be set to enable or disable. If enabled, the
initial unsolicited message is sent when the master opens a connection to the IED, the first
time after a IED reboot. All other unsolicited response parameters are irrelevant if UR
mode is disabled.
Enabling UR mode on a serial multidrop line is not recommended.
Collisions will result from multiple IEDs reporting concurrent events.
Although the DNP3 application layer will recover, collision recovery can
create significant traffic.
UR retries is the number of times the slave will resend the unsolicited response if it is not
confirmed by the master station.
UR TO is the unsolicited response timeout period in milliseconds. This timeout period
starts after App confirm TO expires. A new unsolicited response is transmitted when UR
TO expires. Application layer confirmations received from the master during the UR TO
period are not acknowledged by the IED.
UR offline interval is the unsolicited message offline interval in minutes. Offline interval
starts after the last UR retry. Offline interval never starts when UR retries = 65535
(0xFFFF).
UR Class 1,2,3 Min events are the class 1, 2 or 3 number of events that must accumulate
before they are sent as unsolicited messages, unless the UR Class 1,2,3 TO expires causing
the transmission of the events.
UR Class 1,2,3 TO is the time in ms, that class 1, 2 or 3 events are delayed before being
sent out, unless a count of UR Class 1,2,3 Min events have accumulated causing the
transmission of the events.
Legacy master UR provides compatibility to some older DNP3 masters. When set to
disabled, the slave follows the DNP3 standard, sending its first unsolicited message after
a connection has been established following IED reboot. The master is expected to send
1MAC459571-IB C
620 series ANSI
Communication Protocol Manual