Rockwell Automation 1788-CNCHKR ControlNet NetChecker User Manual - Manual (Page 23)

ControlNet NetChecker 23
Rockwell Automation Publication 1788-UM001B-EN-P - August 2012
Impedance mismatches cause reflections on the media:
• Network not correctly terminated.
• Impedance of coaxial cable not equal to 75 Ω .
• High resistance of contact in connectors.
• Incorrect network architecture.
Effect of Attenuation on Signal Edges
Excessive attenuation causes loss of signal:
• Poor quality coaxial cable
–
Resistance too high
– Losses in dielectric
• Overloaded network
–
Too long trunk segment
– Excessive number of nodes per segment
• Impedance mismatches
IMPORTANT Each coaxial segment must be terminated with a 1786-TCAP terminator at each end.
2.000 V/D
100 ns/DIV