Power repeater / power supply according to IEC 61158-2
FOUNDATION FieldbusGeneral
Subject to reasonable modifications due to technical advances.
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Figure 5.3: Use of power supplies on the FOUNDATION Fieldbus
The power supply must always be connected on the physical end of a transmission
line. The maximum distance to the next node depends on the number of field devices
connected in this bus segment. The following table shows an overview of permissible
stub lines.
Table 2 applies with the prerequisite that exactly one field device is connected to a
spur. If more field devices are connected on a spur, the line lengths must be reduced.
You should also take into consideration that the total length of the field bus system is
calculated as follows:
The field bus power supplies have a field bus terminator that cannot be
turned off. For this reason, the power supply must always be connected
at the beginning or end of a transmission line.
Number of field
devices
max. permissible
spur length
1 - 12
120 m
13 - 14
90 m
15 - 18
60 m
19 -24
30 m
25 - 32
1 m
The line lengths specified above apply exclusively to non-Ex applica-
tions
Note the definition of spur length on
SPS
FOUNDATION Fieldbus H1 bus
Linking
Power supply
Power repeater
Device
