AUMA AUMATIC AC 01.2 Manual page 15

Actuator controls
AC 01.2/ACExC 01.2 Foundation Fieldbus
Bus cables
For details regarding the different topology options, please refer to the Application
Guides published by Fieldbus Foundation:
AG-140 31.25 kbit/s Wiring and Installation
AG-163 31.25 kbit/s Intrinsically Safe Systems
AG-170 Function Block Capabilities in Hybrid/Batch Applications
AG-181 System Engineering Guidelines
Various types of fieldbus cables can be applied for Foundation Fieldbus. The following
table lists the cable types specified by the IEC/ISA 61158-2 Physical Layer Standard.
Type A is the preferred fieldbus cable. This cable should be used in new installations.
However, other cable types may be used for the fieldbus wiring (e.g type B, C, and
D). Their disadvantage is the reduced cable length; therefore, their use is not
recommended.
Table 1: Bus cables
Cable design
Cross section
(nominal)
Loop resistance
(DC current)
Impedance
at 31.25 kHz
Wave attenuation
at 39 kHz
Capacitive asymmetry
Group delay distortion (7.9
39 kHz)
Degree of shield coverage
Recommended network ex-
pansion (incl. spur lines)
General information regarding Foundation Fieldbus
Type A Type B
(Reference)
Twisted con- One or mul-
ductor pair tiple twisted
conductor
pairs, overall
shield
2 2
0.8 mm (AWG 0.32 mm
18) (AWG 22)
44 Ω/km 112 Ω/km
100 Ω 100 Ω
±20 % ±30 %
3 dB/km 5 dB/km
2 nF/km 2 nF/km
1.7 μs/km Not specified
90 % Not specified
1,900 m. 1,200 m
Type C Type D
Multiple twis- Multiple twis-
ted pairs, not ted pairs, not
shielded shielded
2 2
0.13 mm 1.25 mm
(AWG 26) (AWG 16)
264 Ω/km 40 Ω/km
Not specified Not specified
8 dB/km 8 dB/km
Not specified Not specified
Not specified Not specified
Not specified Not specified
400 m 200 m
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