Endress+Hauser PROline prosonic flow 93 Operating Instructions Manual page 45

PROline Prosonic Flow 93 PROFIBUS-DP/-PA
Endress+Hauser
Maximum overall cable length
The maximum network expansion depends on the type of explosion protection and the
cable specifications. The overall cable length is made up of the length of the main cable
and the length of all spurs (>1 m). Note the following points:
x The maximum permissible overall cable length depends on the cable type used.
Type A 1900 m
Type B 1200 m
x If repeaters are used the maximum permissible cable length is doubled.
A maximum of four repeaters are permitted between master and station.
Maximum spur length
The line between distribution box and field device is described as a spur.
In the case of non-Ex applications the max. length of a spur depends on the number of
spurs (>1 m):
Number of spurs
Max. length per spur
Number of field devices
In systems that meet FISCO in the EEx ia type of protection, the line length is limited to
max. 1000 m.
A maximum of 32 users per segment in non-Ex areas or a maximum of approximately
10 stations in an Ex-area (EEx ia IIC) are possible. The actual number of stations must
be determined during the project planning.
Bus termination
The start and end of each fieldbus segment are always to be terminated with a bus
terminator. With various junction boxes (non-Ex) the bus termination can be activated
via a switch. If this is not the case a separate bus terminator must be installed. Note the
following points in addition:
x In the case of a branched bus segment, the device furthest from the segment coupler
represents the end of the bus.
x If the fieldbus is extended with a repeater then the extension must also be terminated
at both ends.
Shielding and grounding
See PROFIBUS-DP cable specifications on o Page 42
Further information
General information and further notes regarding the wiring can be found in the
Operating Instructions BA 198F/00/en: "Field Communication - PROFIBUS-DP/-PA:
Guidelines for project planning and commissioning".
1...12 13...14 15...18
120 m 90 m
4 Wiring
19...24 25...32
60 m 30 m 1 m
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