Siemens PC 670 - Manual (Page 58)

Connecting and Switching on the Computing Unit Release 04/02
3-24 Panel PC 670 Computing Unit, Equipment Manual
3.9 Networking the Computing Unit and Other Nodes via PROFIBUS
Networking the computing unit via PROFIBUS
PROFIBUS is an open and robust bus system for industrial use. It can be used
to configure networks with up to 32 nodes per segment. PROFIBUS-DP
supports data rates of 9.6 KBaud to 12 MBaud.
How the network functions
The network operates on the ”token passing with subordinate master/slave”
principle (complying with DIN 19245, PROFIBUS). It distinguishes between active
and passive nodes. An active node receives the token and passes it on to the next
node within a specified time.
Hardware requirements
Using the following components, for example, you can connect or network the
computing unit to/with PROFIBUS:
S
interface RS 485, MPI/DP interface, integrated
S
shielded, twisted pair cable (bus cable or spur line)
Note
Please refer to the SIMATIC NET Catalog IK IP for more information on the
SIMATIC Net PC cards.