Topology; Cable Lengths; Cable Specifications - Siemens SITRANS F M MAGFLO series Operating Manual

DeviceNet add-on module

3.2 Topology

3.3 Cable lengths

3.4 Cable specifications

6
3. Installation
The DeviceNet allows a mixed trunk line/drop line topology. The cable has to be terminated
with a resistor of 121 ohm/0.25W in both ends of the cable.
Baud rate Max. total
cable length [m]
125 K baud 500 meters (1640 ft.)
250 K baud 250 meters (820 ft.)
500 K baud 100 meters (328 ft.)
Electrical characteristics
Impedance
Propagation delay
Cap. between conductors
Cap. conductors/shield
Cap. unbalance
DCR - @20°C
Attenuation
SFIDK.PS.023.C2.02
Drop length [m]
Maximum
6 meters (20 ft.) 156 meters (512 ft.)
for one drop 78 meters (256 ft.)
39 meters (128 ft.)
Specifications
120 Ohms +/− 10%
1.36 nSec/ft. (max.)
12 pf/ft. (nominal)
24 pf/ft. (nominal)
1200 pf/1000 ft. (max.)
28 Ohms/1000 ft. (max.)
0.29 db/100 ft. @ 125 kHz
0.50 db/100 ft. @ 250 kHz
0.70 db/100 ft. @ 500 kHz
Cumulative