GE GFK-2193A - Manual (Page 11)

2-2 Series 90™-30 PROFIBUS Slave Module User's Manual – August 2004 GFK-2193A
2
Connecting the Slave to the PROFIBUS Network
Network Segment Length
A PROFIBUS network uses either fiber optic or RS-485 copper media. The copper bus
line specified in EN 50 170 is “Line Type A” and is the recommended cable type. A more
economical copper cable “Line Type B” is commonly used for smaller installations;
however, it is not specified in EN 50 170. It is extremely important to use cable rated to
PROFIBUS specifications. The higher the baud rate selected and the longer the distances
involved, the more critical cable selection becomes. (PROFIBUS cable has a distinctive
purple color.)
Stub or “T” type branch connections are supported if the total stub (branch) lengths do not
exceed 6.6 meters. Do not use stubs at all on 12 Mbaud networks.
The data rates for network communication with maximum segment trunk length per cable
type are provided below. Multiple segments may be connected via repeater stations to
extend the total bus length.
Line Types
Baud Rate Line A
Distance (Max) 1, 2
Line B
Distance (Max) 1, 2
Glass Fiber
9.6KBps, 19.2KBps and 93.75KBps 1200 m 1200 m 6Km
187.5KBps 1000 m 600 m 6Km
500KBps 400 m 200 m 6Km
1.5MBps 200 m NA 6Km
3, 6 and 12MBps 100 m NA 6Km
1 If using a combination of both line types, divide the lengths shown by two.
2 Values shown are the sum of all bus segment and drop cable lengths.
NA = Not Applicable
Note: The two physical ends of the PROFIBUS network should be terminated. There
should be two, and only two, terminators on a network.