ABB RELION REX640 Operation Manual page 121

1MRS759118 D
7.4.2.4 Physical locations of the serial channels
The physical location of the COM1 and COM2 drivers depends on the link mode
used which, in turn, depends on the used communication hardware option. Serial
channels can be found on communication boards COM1004...COM1005.
• X7 is the fiber-optic interface. Only driver COM2 can be configured into fiber-
optic mode.
• X8 is the RS-485/IRIG-B interface. Both drivers COM1 and COM2 can be
configured to this interface: COM1 and COM2 can act as two RS-485 2-wire links
or, alternatively, COM1 can act as one single RS-485 4-wire link. Both ports are
galvanically isolated serial communication ports.
Table 18: Connector X8 signals
Pin No
1
2
3
4
5
6
7
8
9
10
10
8
6
4
2
Figure 102: X8 connector pinout for socket on communication board
REX640
Operation Manual
Pin name
GND
GNDC
NC
IRIG-B -
IRIG-B +
ISOL_GND
RS485 B1/-
RS485 A1/+
RS485 B2/-
RS485 A2/+
9
7
5
3
1
Description Alternative
EARTH
GND connected to
earth via 1nF capaci-
tor
ISOL2_GND
RS485 GND
2-wire - , COM1 4-wire TX pair, COM1
2-wire + , COM1 4-wire TX pair, COM1
2-wire - , COM2 4-wire RX pair, COM1
2-wire + , COM2 4-wire RX pair, COM1
Commissioning
121