Siemens Automation System S7-400 - Manual (Page 114)

Networking
5-16
Automation System S7-400 Hardware and Installation
A5E00850741-01
Lengths of Spur Lines
If you do not fit the bus cable directly at the bus connector (for example, when
using a PROFIBUS-DP bus terminal), you must take into account the maximum
possible spur line length.
The following table gives the maximum lengths of spur lines allowed per bus
segment:
Table 5-3 Lengths of Spur Lines per Segment
Transmission Rate Maximum
Length of a
S Li
Number of Nodes per
Spur Line Length of ...
Maximum
Length of
S Li
g
Spur Line
1.5 m and
1.6 m
3 m
g
Spur Lines
per Segment
9.6 to 93.75 kbps 3 m 32 32 96 m
187.5 kbps 3 m 32 25 75 m
500 kbps 3 m 20 10 30 m
1.5 Mbps 3 m 6 3 10 m
A spur line is not permissible with transmission rates greater than 1.5 Mbps.
To connect a programming device or PC, use the connecting cable for the
programming with theorder number 6ES7901-4BD00-0XA0. You can use several
connecting cable with this order number for programming devices in one bus
configuration.