Section 3
Physical connections
3.1
Serial ports
The device has two 9-pin male serial port connectors (DB9). A null modem cable
can be used to connect the device to a serial device or a PC. The device supports
CTS/RTS flow control.
GUID-9F6668AA-EBAB-46B5-A1AF-35D8AE3E6C12 V1 EN
Figure 9:
DB9 (DTE) male connector
3.1.1
Serial port 2
The serial port 2 (RS2) can be configured either as a half-RS-232 or an RS-422/485
(DTE Master). The pin description is the same as in RS1, when the port is in the
RS-232 mode.
Do not connect the RS-422 or RS-485 devices to a port which has
been configured to operate as an RS-232 port.
Table 5:
RS-485 port PIN description
Pin number
RS-485 full duplex (4-wire)
RS-485 half-duplex (2-wire)
1
NC
NC
2
RXD+ (in)
NC
3
TXD- (out)
TXD/RXD- (out/in)
4
NC
NC
5
GND
GND
6
NC
NC
7
TXD+ (out)
TXD/RXD+ (out/in)
8
RXD- (in)
NC
9
NC
NC
1MRS757105 B
Section 3
Physical connections
RER601/603
15
Technical Manual