The profibus bus node, Configuration of the 9-pole sub-d connector, Separate potentials – Burkert Type 8644 User Manual

Page 37

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8644/phoenix - 33

S

YSTEM

D

ESCRIPTION

The Profibus bus node

Installation and electrical commissioning of the field bus node
Profibus DP

Display / LEDs

Address setting

9-pole SUB-D Profibus connector

Supply terminals
(for configuration, see
following page)

Configuration of the 9-pole SUB-D connector

As a general rule, a 9-pole SUB-D connector with pins is used in the PROFIBUS. In the profibus DP field
bus coupler, the matching part (socket) is always present. In the first and last plugs of a segment, a
closing resistor of 220 ohm and two terminating resistors of 390 ohm must be present. The A line (RxD/
TxD-P) is always earthed via one terminating resistor, the B line (RxD/TxD-P) is always connected to +5V
via the other one. These resistors must be provided in the plug (e.g. Phoenix Contact SUNCON-PLUS-
PROFIB, Art. no. 27 44 34 8).

Separate potentials

The interface supply for the Profibus has a separate potential from that of the power supplies. When using
an LWL converter, the voltage shut-off to the 5 V logic supply to the bus terminal can be cancelled via DIP
switches 9 an 10. This makes the higher current required for operating the LWL converter available at the
interface.

* Removal of potential separation

Pin No.

Designation (socket in device, plug on

cable)

Meaning

1

n. c.

-

2

n. c.

-

3

RxD / TxD-P

Receive / send data P (+) (conductor B)

4

CNTR-P

Control signal for repeater (+), direction control

5

DGND*

Reference potential of 5 V

6

VP*

Supply voltage + 5 V for closing resistors

7

n. c.

-

8

RxD/TxD-N

Receive / send data N (-) (conductor A)

9

n. c.

-

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