ABB REX 521 Technical Reference Manual, General

1MRS 751108-MUM
REX 521
39
Protection Relay
Technical Reference Manual, General
4.1.12.9. DNP 3.0 Bus
The REX 521 can also be connected to a DNP 3.0 system.
The DNP 3.0 protocol is used in a substation automation system for connecting the
protection devices to a system level device. A daisy chain network configuration is
used and the physical interface is made by two-wire RS-485 (see Figure 4.1.12.9.-
1). Optical RS-232 interface (star-topology) is also possible to use with DNP 3.0 in
REX 521.
The transmission speed is configurable up to 19200 kbits/s and support for
unsolicited messages is included.
Fig. 4.1.12.9.-1 Example of a DNP 3.0 system
For more information of DNP 3.0 in REX 521, see DNP 3.0 Communication
Protocol for REF 54_ and REX 521 Technical Description (see “Related
documents” on page 7).
4.1.13. Time synchronization
The time synchronization (Configuration\Time) of the protection relay can
be given from different sources:
1. The time can always be given manually from the front panel.
2. The time synchronization can also be given externally. The master parameter for
external synchronization source selection is called Sync. source. This
parameter can have two different states:
• “Net Messages” state
• “X3.1.2 Input” state
DNP 3.0 Master
C
E
F
I
0
REF 54_ relays
REX 521
REX52x REX52x
REX5 2x
RER 133
RS232 RS485
RS485 INTERFACE
12345678
4 WIRE TERMINATED
S1
OFFON ON OFFOFF NC NC NC
S2 ON ON ON ON ON ON NC NC
4 WIRE WITHOUT TERMINATION
S1
OFFON ON OFFOFF NC NC NC
S2 OFFOFFOFFOFF OFFOFF NC NC
2 WIRE TERMINATED
S1
ONOFF ON OFFOFF NC NC NC
S2 OFFOFFOFF ON ON ON NC NC
2 WIRE WITHOUT TERMINATION
S1
ONOFF ON OFFOFF NC NC NC
S2 OFFOFFOFFOFF OFFOFF NC NC
S1
S2
ON
ON
OFF
OFF
2WIRE
8A +
7 B 
6A +
5 B 
4AGND
3NC
2 Shield GND C
1 Shield GND
4WIRE
RX
TX

RER133_front_a
C
E
F
I
0
RER 133
RS232 RS485
RS485 INTERFACE
12345678
4 WIRE TERMINATED
S1
OFFON ON OFFOFF NC NC NC
S2 ON ON ON ON ON ON NC NC
4 WIRE WITHOUT TERMINATION
S1
OFFON ON OFFOFF NC NC NC
S2 OFFOFFOFFOFF OFFOFF NC NC
2 WIRE TERMINATED
S1
ONOFF ON OFFOFF NC NC NC
S2 OFFOFFOFF ON ON ON NC NC
2 WIRE WITHOUT TERMINATION
S1
ONOFF ON OFFOFF NC NC NC
S2 OFFOFFOFFOFF OFFOFF NC NC
S1
S2
ON
ON
OFF
OFF
2WIRE
8A +
7B 
6A +
5B 
4AGND
3NC
2 Shield GND C
1 Shield GND
4WIRE
RX
TX

RER133_front_a
C
E
F
I
0
RER 133
RS232 RS485
RS485 INTERFACE
12345678
4 WIRE TERMINATED
S1
OFFON ON OFFOFF NC NC NC
S2 ON ON ON ON ON ON NC NC
4 WIRE WITHOUT TERMINATION
S1
OFFON ON OFFOFF NC NC NC
S2 OFFOFFOFFOFF OFFOFF NC NC
2 WIRE TERMINATED
S1
ONOFF ON OFFOFF NC NC NC
S2 OFFOFFOFF ON ON ON NC NC
2 WIRE WITHOUT TERMINATION
S1
ONOFF ON OFFOFF NC NC NC
S2 OFFOFFOFFOFF OFFOFF NC NC
S1
S2
ON
ON
OFF
OFF
2WIRE
8A +
7B 
6A +
5B 
4AGND
3NC
2 Shield GND C
1 Shield GND
4WIRE
RX
TX

RER133_front_a
RS-485 twisted pair
DNP_sys_REXREF_a
RER 133
RER 133
RER 133

ABB REX 521 Specifications

General

Brand	ABB
Model	REX 521
Category	Other
Language	English