Transmission Rate/Cycle Times; Transmission Cables; Use Of Drop Lines - turck IO-LINK MASTER User Manual

PROFIBUS-DP

Use of Drop lines

Transmission rate/Cycle times

The transmission rate set by the PROFIBUS-DP master determines the system's transmission
speed. Depending on the gateway, the transmission speed can be adjusted in a range of 9,6
kbps up to 12 Mbps.

Transmission cables

The bus nodes are interconnected via fieldbus cables, which accord to RS485 specifications
and DIN19 245. The cables must thus have the following characteristics:
Table 2: Parameters
Characteristics
Wave resistance
of PROFIBUS-
DP transmission
Capacitance
cables
Loop resistance
Conductor diameter
Conductor cross section
Terminating resistors
Figure 1:
Vp
Schematic
PROFIBUS-DP
cables
R t
GND
1-4
Note
The length of drop lines may not exceed 6.6 m at a transmission speed of 1.5 Mbps.
At a transmission speed of 12 Mbps it is not permitted to use drop lines.
Cable type A (DIN 19 245 part 3)
135 to 165 Ω (3 to 20 MHz)
< 30 pF/km
< 110 Ω/km
> 0.64 mm
> 0.34 mm
220 Ω
Attention
The higher the transmission rate, the higher the number of bus nodes and the longer
the transmission cables, the more important to observe these parameters.
Shield
Vp
R t
GND
Teilnehmer 0
Station 0
2
inside:
Twisted cable pair
Schirm innenliegend:
verdrillte Zweidrahtleitung
Vp
Vp
R t
R t
terminating
Abschluß-
widerstand
resistor
GND
GND
Teilnehmer 31
Station 31
D301171 - IO-Link master 1108