SmartFlex SR309
5.10.2
RS232-RS485/422 interface
These interfaces are physically connected through the 5-pin and 4-pin terminal block con-
nectors. The insulation strength is up to 2.5 kV.
Attention, connectors are not isolated from
each other!
No state indication is displayed for this interface. These router versions comply
with the standards and temperature ranges stated in Chap.
Figure 30: Version with RS232-RS485/422 interface
When connecting counterpart terminal block connectors (included in package with the router),
use cables with nominal cross section 0.2 to 1.0 square mm (30 to 16 AWG). Recommended
stripping length is 5 mm. For M2 captive screws the screw driver 0.5 x 3 mm is recommended.
Tighten the screws with 0.3 Nm torque.
Connection of RS232 connector:
Pin
Signal
Description
Direction
1
CTS
Clear To Send
Output
2
RTS
Request To Send
Input
3
GND
Signal ground
∗
—
4
RXD
Receive Data
Input
5
TXD
Transmit Data
Output
Table 17: Connection of RS232 connector
∗
Both connectors (RS232 and RS485/422) have a common ground connection.
31
