Fieldbus controller 750-842 • 51
Hardware
Modular I/O System
ETHERNET TCP/IP
3.2.2.3 Fieldbus
connection
Connection to the fieldbus is by a RJ45 connector. A category 5,
shielded/unshielded twisted pair cable (S-UTP) with an impedance of 100
Ohm
±
15% is mandatory as a connecting line for the 10BaseT Interface.
The connection point is physically lowered for the coupler/controller to fit in
an 80 mm high switch box once connected.
The electrical isolation between the fieldbus system and the electronics is
achieved by means of DC/DC converters and optocouplers in the fieldbus in-
terface.
Contact
Signal
1
TD +
Tr
2
TD -
Transmit -
3
RD +
R
4
free
5
free
6
RD -
Receive -
7
free
8
free
Fig. 3-19: RJ45-connector and RJ45 connector configuration
3.2.2.4 Display
elements
The operating condition of the fieldbus controller or node is displayed via light
diodes (LED).
24V 0V
+ +
01 02
ON
LINK
TxD/RxD
I/O
ETHERNET
C
D
B
A
ERROR
USR
status
voltage supply
-power jumper contacts
-system
Fig. 3-20: Display elements 750-842
G
012902e
LED
Color
Meaning
ON
green
Fieldbus initialization is correct
LINK
green
Link to a physical network exists
TxD/RxD
green
Data exchange taking place
ERROR
red
Error on the fieldbus
IO
red /green
/ orange
The ’I/O’-LED indicates the operation of the node and signals faults
encountered
USR
red /green
/ orange
The ’USR’ LED can be selected by a user program in a programma-
ble fieldbus controller
A
green
Status of the operating voltage – system
C
green
Status of the operating voltage – power jumper contacts