3.2 Assignment of the interface X4A
5
4
3
2
1
9
8
7
6
reserved
1
6
reserved
TxD (RS232)
2
7
DGND (reference potential)
RxD (RS232)
3
8
TxD-A (RS485)
RxD-A (RS485)
4
9
TxD-B (RS485)
RxD-B (RS485)
5
Figure 3:
Assignment of the interface X4A
3.2.1 Connection of the RS232 interface
A RS232 cable is required to connect the control board with a PC. Transmission rate of
1.2…100 kBaud is possible.
0058025-001D
1
5
6
9
1
5
6
9
Figure 4:
Serial cable to connect the control board with a PC
3.2.2 Connection of the RS485 interface
ATTENTION
The following instructions must be observed in order to prevent interfer-
ences at the RS485 interface:
• Use in pairs, twisted and shielded cable.
• Ground outer shield at one side (prior at interference-free side).
•
Connect terminating resistors (120 Ω) at both ends on pair of wires
of the communication bus.
• If available, the internal shielding must be laid at the transmitter to
ground.
• Lay earth cable between the bus nodes.
A biasing can be used if there are still interferences. However, this should be
done only once at the communication bus (preferably at the master).
17
CONTROL CIRCUIT ANALOG/DIGITAL
