Siemens Simovert Masterdrives Compendium page 377

09.2008
8.2.6 Connecting up the CBP to the PROFIBUS
8.2.6.1 Assignment of plug-in connector X448
Connecting up
5
9
6
1
8.2.6.2 Connecting up the bus cable by means of the RS485 bus connecting
system
Maximum cable
lengths
Siemens AG 6SE7087-6QX70 (Version AK)
SIMOVERT MASTERDRIVES
The CBP optional board has a 9-pin Sub-D socket (X448) which is
provided for connecting the CBP to the PROFIBUS system. The
connections are short-circuit proof and floating.
Pin Designation
1 SHIELD
2 -
3 RxD/TxD-P
4 CNTR-P
5 DGND PROFIBUS data reference potential (C/C´)
6 VP
7 -
8 RxD/TxD-N
9 -
Table 8.2-9 Pin assignment of X448 connection
With the PROFIBUS, data transfer according to RS485 is most frequently
used. A twisted, shielded copper cable with one pair of wires is used.
Up to a maximum of 124 units can be connected to a PROFIBUS phase.
In one bus segment, up to 32 units can be connected together in a linear
structure. If there are more than 32 nodes, repeaters (power amplifiers)
must be used in order to link up the individual bus segments.
The maximum cable length depends on the baud rate (transmission
speed).
The maximum cable length can be increased by using repeaters but no
more than three repeaters may be connected in series.
The maximum cable lengths given in the following table can only be
ensured if PROFIBUS bus cables are used (e.g. Siemens PROFIBUS-
cable with MRPD 6XV 1830-0AH10).
Baud rate
9.6 to 187.5 kbaud
500 kbaud
1.5 Mbaud
3 to 12 Mbaud
Table 8.2-10 Permissible cable length of a segment with RS485 repeaters
Compendium Motion Control
Significance
Ground connection
Not connected
Receive/transmit data P (B/B´)
Control signal
Power supply Plus
Not connected
Receive/transmit data N (A/A´)
Reference filtered
Max. cable length in
a segment
[m]
1000
400
200
100
Communication / PROFIBUS
Area
RS485
TTL
5 V ± 10 %
RS485
M_EXT
Max. distance between 2
stations
[m]
10000
4000
2000
1000
8.2-47