Rockwell Automation 1794-APBDPV1 FLEX I/O PROFIBUS Adapter User Manual - Manual (Page 83)

71 Publication 1794-UM064B-EN-P - May 2014
Chapter
3
Connect Your Adapter to the PROFIBUS DP
Network
Overview Read this chapter to install the input and output analog modules.
The DP Physical Layer The PROFIBUS network media is a balanced transmission line corresponding to
the standard EIA RS-485, terminated at both ends. Both line A and line B types
are available, depending on your system requirements.
Specifications and guidelines for DP media:
• linear bus, terminated at both ends
• drop cables (preferably no longer than .30 m), no branches
• shielded twisted pair
• max. line length between 100 and 1200 m (depending on baudrate and
cable type)
• number of stations: 32
• DP baudrates: 9.6, 19.2, 93.75, 187.5, 500 Kbit/s, 1.5 Mbit/s, 12 MBd
Use the following table to determine what line type will best meet your needs.
For Information On Page
The DP Physical Layer 71
Cabling and Equipment Required for Line A Type 72
Cabling and Equipment Required for Line B Type 73
Connect the Adapter to the Network 74
Terminate the Network 76
Line Type Characteristics
Characteristic Bus Segments and Drop Cables (1)
Line A Requirements
(2)
Line B Requirements Total Capacity of
all Drop Cables
Impedance 135…165 Ω (3-29 MHz) 100…130 Ω (f> 100 kHz)
Capacity < 30 pF/m < 60 pF/m
Resistance < 110 Ω/km –
Wire Gauge > 0.64 mm > 0.53 mm
Conductor Area > 0.34 mm > 0.22 mm