3.10 Bus cables
Only cables according to standard DIN 19245 or EN 50170-2, cable type A,
may be used for Profibus DP wiring.
A maximum of up to 32 Profibus devices may be connected in one segment.
If more devices are to be connected to one Profibus network, several
segments must be connected with repeaters.
The bus cable must be laid at a distance of at least 20 cm from other cables.
It should be laid in a separate, conductive and earthed cable trunking.
It must be ensured that there are no potential differences between the indi-
vidual devices on the Profibus (perform a potential compensation).
Cable specification cable type A for Profibus DP
Characteristic impedance:
135 to 165 Ohm, at a frequency
of 3 to 20 Mhz.
Cable capacity:
< 30 pF per meter
Core diameter
> 0.64 mm
Core cross section:
> 0.34 mm², corresponds to AWG 22
Loop resistance:
< 110 Ohm per km
Screening:
Copper shielding braid or shielding braid and
shielding foil
12
Actuator controls AUMA MATIC AM/ AMExB/ AMExC
Profibus DP
Short instructions bus connection
Transmission rate in kBit/s
≤
93.75
187.5
500
1500
Maximum segment length in m
1200
1000
400
200
Table 5
Figure E: Example: Profibus with one segment
Bus termination
switched on
Bus termination
switched on
Profibus DP board
AUMA MATIC
Profibus DP
Connection
board
2-wire cable
Controls (master)