Technical data
42
1MRS751108-MUM
Protection Relay
Technical Reference Manual, General
REX 521
The adjustable parameters via HMI for Modbus communication in REX 521 are
CRC Order, Modbus Mode, Unit Address, Baud rate, No of stop
bits, No of data bits, End of frame TO, and Parity.
For more information on Modbus, see Modbus Remote Communication Protocol for
REX 521, Technical Description (see “Related documents” on page 10).
5.1.12.9. 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 Fig. 5.1.12.9.-1).
It is also possible to use an optical RS-232 interface (star-topology) for DNP 3.0 in
REX 521.
The transmission speed is configurable up to 19200 kbits/s and support for
unsolicited messages is included.
A051914
Fig. 5.1.12.9.-1 Example of a DNP 3.0 system
For more information of DNP 3.0 in REX 521, see the manual DNP 3.0
Communication Protocol for REF 54_, RET 54_ and REX 521, Technical
Description (see “Related documents” on page 10).
When using the RTU mode, every time the bit rate parameter (Baud
rate) is reconfigured, that is, the value is changed, the software of
REX 521 also recalculates the default value for the timeout
parameter (End of frame TO). Therefore, to manually enforce
the timeout value, the timeout parameter must always be set after the
Baud rate parameter is configured. In this case it is
recommended to set the parameter value to a longer timeout than the
calculated default value with the Baud rate parameter in
question.
REX 521
RER 133
RS232 RS485
RS485 INTERFACE
12345678
4 WIRE TERMINATED
S1
OFFON ONOFFOFF NC NC NC
S2
ONON ON ON ON ON NC NC
4 WIRE WITHOUT TERMINATION
S1
OFFON ONOFFOFF NC NC NC
S2
OFFOFFOFFOFFOFF OFF NC NC
2 WIRE TERMINATED
S1
ONOFF ON OFF OFF NC NC NC
S2
OFFOFFOFF ON ONON NC NC
2 WIRE WITHOUT TERMINATION
S1
ONOFF ON OFF OFF NC NC NC
S2
OFFOFFOFFOFFOFF OFF NC NC
S1
S2
ON
ON
OFF
OFF
2WIRE
8A +
7B
6A +
5B
4 AGND
3NC
2 Shield GND C
1Shield GND
4WIRE
RX
TX
RER133_front_a
RER 133
RER 133
RER 133
REX 521
READY START TRIP
FEEDER PROTECTION
REX 521
READY START TRIP
FEEDER PROTECTION
REX 521
READY START TRIP
FEEDER PROTECTION
REF 541
Uaux = 80...265 Vdc/ac
fn = 50 Hz
In = 1/5 A (I)
1MRS xxxxxx
98150
9509
Ion = 1/5 A (Io)
Un = 100/110 V (U)
Uon = 100/110 V (Uo)
21 kV
CB OK
AROFF
REF 541
Uaux = 80...265 Vdc/ac
fn = 50 Hz
In = 1/5 A (I)
1MRS xxxxxx
98150
9509
Ion = 1/5 A (Io)
Un = 100/110 V (U)
Uon = 100/110 V (Uo)
21 kV
CB OK
AROFF
REF 541
Uaux = 80...265 Vdc/ac
fn = 50 Hz
In = 1/5 A (I)
1MRS xxxxxx
98150
9509
Ion = 1/5 A (Io)
Un = 100/110 V (U)
Uon = 100/110 V (Uo)
21 kV
CB OK
AROFF
RER 133
RS232 RS485
RS485 INTERFACE
12345678
4 WIRE TERMINATED
S1
OFFON ONOFFOFF NC NC NC
S2
ONON ON ON ON ON NC NC
4 WIRE WITHOUT TERMINATION
S1
OFFON ONOFFOFF NC NC NC
S2
OFFOFFOFFOFFOFFOFFNCNC
2 WIRE TERMINATED
S1
ONOFF ON OFF OFF NC NC NC
S2
OFFOFFOFF ON ONON NC NC
2 WIRE WITHOUT TERMINATION
S1
ONOFF ON OFF OFF NC NC NC
S2
OFFOFFOFFOFFOFFOFFNCNC
S1
S2
ON
ON
OFF
OFF
2WIRE
8A +
7B
6A +
5B
4 AGND
3NC
2 Shield GND C
1 Shield GND
4WIRE
RX
TX
RER133_front_a
RER 133
RS232 RS485
RS485 INTERFACE
12345678
4 WIRE TERMINATED
S1
OFFONONOFFOFFNCNCNC
S2
ONON ON ON ON ON NC NC
4 WIRE WITHOUT TERMINATION
S1
OFFONONOFFOFFNCNCNC
S2
OFFOFFOFF OFF OFFO FF NC NC
2 WIRE TERMINATED
S1
ONOFF ON OFF OFF NC NC NC
S2
OFFOFFOFF ON ONON NC NC
2 WIRE WITHOUT TERMINATION
S1
ONOFF ON OFF OFF NC NC NC
S2
OFFOFFOFF OFF OFFO FF 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 3.0 Master
REF 54_ terminals