CHAPTER 3 WIRING, CONNECTING
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3.1 Physical interface
Isolation: The bus is galvanically separated from the other electronics with an on board DC/DC converter. Bus
signals (A-line and B-line) are isolated via photo couplers.
Profibus-DP communication ASIC: VPC3 chip from ProfiChip.
Bus connection: The SJ-PB connects to the Profibus network with a 9-pin female DSUB connector. For the pin
layout, refer to Table 3-1.
Table 3-1 Pin Layout of SJ-PB
Pin
Name
Function
Housing
Shield
Connected to PE
1
Not Connected
-
2
Not Connected
-
3
B-Line
Positive RxD/TxD according to RS 485 specification
4
RTS
Request To Send (note)
5
GND BUS
Isolated GND from RS 485 side (note)
6
+5V BUS
Is5V from RS 485 side (note)
7
Not Connected
-
8
A-Line
Negative RxD/TxD according to RS 485 specification
9
Not Connected
-
(note) +5V BUS and GND BUS are used for bus termination. Some devices, like optical transceivers (RS485 to
fibre optics) might require external power supply from these pins. RTS is used in some equipment to determine
the direction of transmission. In standard applications only A-Line, B-Line and Shield are used.
The SJ-PBT connects to the Profibus network with a 6-poles 2pieces connector. For the pin layout, refer to
Table 3-2.
Table 3-2 Pin Layout of SJ-PBT
Pin
Name
Function
1
B-Line(in)
Positive RxD/TxD according to RS 485 specification
2
A-Line(in)
Negative RxD/TxD according to RS 485 specification
3
Shield
Connected to PE
4
B-Line(out)
Positive RxD/TxD according to RS 485 specification
5
A-Line(out)
Negative RxD/TxD according to RS 485 specification
6
Shield
Connected to PE
3.2 Profibus connectors
On the SJ-PB, any standard Profibus connector can be used. Depending on baudrate, IP-classing and physical
size of connector there are several different manufacturers and models, the prizing may also vary. For more
information it is recommended to contact the manufacturer, e.g., Siemens or Erni.
SJ-PBT: In this case, the network connector is attached with SJ-PBT option board.
