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4 Wiring
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24
4
Wiring
Warning!
• When connecting Ex-certified devices, see the notes and diagrams in the Ex-specific supplement
to these Operating Instructions. Please do not hesitate to contact your E+H representative if you
have any questions.
• For the remote version, always make sure that you connect the sensor only to the transmitter hav-
ing the same serial number. Communication errors can occur if the devices are not connected in
this way.
4.1
Cable specifications for PROFIBUS PA
Cable type
Twin-core cables are required for connecting the device to the fieldbus. By analogy with
IEC 61158-2 (MBP) protocol four different cable types (A, B, C, D) can be used with the fieldbus
protocol, only two of which (cable types A and B) are shielded.
• Cable types A or B are particularly preferable for new installations. Only these types have cable
shielding that guarantees adequate protection from electromagnetic interference and thus the
most reliable data transfer. On multi-pair cables (type B), it is permissible to operate multiple field-
buses (with the same degree of protection) on one cable. No other circuits are permissible in the
same cable.
• Practical experience has shown that cable types C and D should not be used due to the lack of
shielding, since the freedom from interference generally does not meet the requirements
described in the standard.
The electrical data of the fieldbus cable have not been specified but determine important character-
istics of the design of the fieldbus, such as distances bridged, number of users, electromagnetic com-
patibility, etc.
Cable structure
Wire size
Loop resistance (DC)
Impedance at 31.25 kHz
Attenuation at 39 kHz
Capacitive asymmetry
Envelope delay distortion
(7.9 through 39 kHz)
Shield coverage
Max. cable length
(incl. spurs >1 m)
* not specified
Cable type A
twisted pair, shielded
2
0.8 mm
(AWG 18)
44 Ω/km
100 Ω ± 20%
3 dB/km
2 nF/km
µ
1.7
s/km
90%
1900 m
Proline Promass 80 PROFIBUS PA
Cable type B
one or more twisted pairs, fully shielded
2
0.32 mm
(AWG 22)
112 Ω/km
100 Ω ± 30%
5 dB/km
2 nF/km
*
*
1200 m
Endress+Hauser
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