Permissible Cable Length Of A Segment Incorporating Rs 485 Repeaters With Order Number 6Es7 972-0Aa00-0Xa0 - Siemens SIMATIC S5 Manual

Cornerstone data In the ET 200 distributed I/O system, you can operate a maximum of 126
for linking bus stations on a single bus. Of this total, a maximum of 124 can be DP slaves.
segments The maximum number of DP slaves you can address with an IM 308-C is
122.
The maximum number of stations per bus segment diminishes with each RS
485 repeater inserted in the system (because of power consumption). This
means as that soon as you include an RS 485 repeater in a segment, the
segment in question can accommodate a maximum of only 31 other stations.
Note that the number of RS 485 repeaters has no effect on the maximum
number of stations connected to the bus.
Up to 10 bus segments can be connected in series. The distance between the
two most widely separated stations must not exceed the appropriate value
shown in the table below.
Table 1-2 Permissible cable length of a segment incorporating RS 485 repeaters with
ET 200 Distributed I/O System
EWA 4NEB 780 6000-02a
order number 6ES7 972-0AA00-0XA0
Baud rate Max. cable length of
a segment (in meters)
9.6 to 187.5 kbaud
500 kbaud
1.5 Mbaud
3 to 12 Mbaud
System overview
Max. distance between 2
stations (in meters)
1000 10000
400 4000
200 2000
100 1000
1
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