ProMinent PROFIBUS DP DULCOMETER diaLog DACb Supplementary Instructions Manual page 7

Plugs and cables
Tab. 2: The maximum overall length of the bus cabling without repeaters varies according to the desired data
transmission rate:
Maximum length of bus cabling
m
100
100
100
200
400
1000
1200
1200
1200
Note for achieving IP 67 degree of
protection
Supplementary instructions PROFIBUS
For the PROFIBUS ® DP cable, use a screened, twisted-pair cable
conforming to EN 50170 (cable type A).
Earthed shielding
Using shielding which is earthed at one end pre‐
vents low-frequency ground loops. Shielding
earthed at one end is not effective in countering
HF magnetic pick-up. Shielding earthed at both
ends as well as twisted conductors are effective in
countering magnetic HF pick-up but are not effec‐
tive against electrical HF pick-up.
For PROFIBUS ® , we would recommend establishing a bilateral,
low-inductance (i.e. large area and low-impedance) connection
with the protective earth.
Data transmission rate
kBit/s
12000
6000
3000
1500
500
187.5
93.75
19.2
9.6
The PROFIBUS DP cable is fitted directly on the terminals of the
®
PROFIBUS ® DP module.
An installation conforming to IP 67 is possible because the cabling
is carried out using the appropriate assembly accessories (cable
passages etc.) directly on the controller terminal.
CAUTION!
Degree of protection IP 67
– IP 67 degree of protection only applies if the
appropriate assembly accessories (cable pas‐
sages etc.) have been correctly installed (see
controller assembly and operating instructions).
If the controller is the last bus device connected to the PROFIBUS
DP cable, it must be connected as a termination using the PRO‐
FIBUS ® DP module (see EN 50170). The terminating resistance
required for this can be activated internally using the
operating menu (network termination). No external terminating
resistance is required.
® DP
®
'Termination'
7