Hirschmann OZD Profi 12M G12 PRO, Manual, Page: 31 / 46

4.9 Connecting the electric bus cables
31
4 Setting Up
Version 04 05/2014
䊳
Only use shielded and twisted-pair wiring as a RS 485
bus line.
䊳
Use a PROFIBUS bus connector plug to connect the
RS 485 bus segment.
Notes:
- If the repeater is at the beginning or end of a bus
segment, this connector must have an activated
bus terminal resistor combination.
- Ensure that the bus segment connected to the
RS 485 interface is terminated at both ends.
- Only use a connecting cable which is terminated at
both ends to connect a single device.
䊳
All PROFIBUS bus connector plugs in a network must
be securely screwed onto the RS 485 interfaces.
䊳
Attaching or removing the bus connector plugs,
inadequately attached bus connector plugs or loose
bus wires within the plug can lead to malfunctions in
the optical and electrical networks.
䊳
Attach or remove the RS 485 bus connector plug
quickly and without twisting them.
䊳
Remove the RS 485 bus line from the OZD Profi if a
device is not connected to the other end, or there is
an OZD Profi which has been disconnected from the
power supply. The open line otherwise acts as an
antenna and can cause inter ference.
䊳
When connecting a RS 485 bus line to the OZD Profi
12M … PRO in an active network, keep to the follo-
wing sequence in order to avoid interference:
1. Place the RS 485 bus connector plug onto the
device which is to be connected (e.g. to a program-
ming device) and screw it on tightly.
2. Attach the RS 485 bus connector plug to the
OZD Profi 12M … PRO quickly and without twisting
the connector, and screw it on tightly.
Proceed in the reverse order when removing a device
from the network.
Data rate Range per segment
12 MBit/s 100 m
6 MBit/s 100 m
3 MBit/s 100 m
1.5 MBit/s 200 m
500 kBit/s 400 m
187.5 kBit/s 1000 m
93.75 kBit/s 1200 m
45.45 kBit/s 1200 m
19.2 kBit/s 1200 m
9.6 kBit/s 1200 m
Table 1: Range of RS 485 bus segment with cable type A
1)
1) Properties of cable type A:
Characteristic impedance 135 - 165 Ohm
Capacity coating _ < 30 pF/m
Loop resistance _ < 110 Ohm/km
Wire diameter > 0.64 mm
Wire cross section > 0.34 mm
2