Rockwell Automation PLC-5 Fieldbus Solutions for Integrated Architecture User Manual - Manual (Page 86)

Publication 1757-UM006A-EN-P - May 2002
3-4 1757-FIM Planning Considerations
Fieldbus wiring selection and calculation
The preferred cable for connecting fieldbus devices is #18 AWG
(0.8mm
2
) shielded, twisted pair wire. It is important to calculate how
the planned topology for your fieldbus segment, selected wiring,
supplied power and intended mix of fieldbus devices may impact the
overall performance of a fieldbus network.
The original Fieldbus specification allows using twisted pair wiring,
which is commonly used for 4-20 ma transmitters.
Windows based, Fieldbus Segment Calculator tools are available in the
market place that can assist you in calculating the performance
characteristics of a planned fieldbus segment.
See Appendix D for a condensed overview of fieldbus wiring
considerations provided for convenient reference. This information
does overlap some information that is found in other data references
as well.
Installing 1757-FIM
Fieldbus Interface Module Refer to the 1757-FIM Installation Instructions, publication
1757-IN0913A-EN-P.
Installing 1757-RTP Remote
Terminator Refer to the 1757-RTP Installation Instructions, publication
1757-IN915A-EN-P.
TIP
We can’t emphasize enough the use of high
quality network (wire) installation. The higher
quality of installation materials the better
performance you will achieve in your network
application
Universal manufacturers sell “Fieldbus cable”
which meets all the specifications required for
“Fieldbus cable”.