Emerson Vission 20/20 Operation And Service Manual page 206

Appendix B • Vission 20/20 Application Procedures
Test 1
The fi rst test measured the noise on the active net-
work WITHOUT the Phoenix Contact PSM-ME isolator
installed in the network, see Figure B-26. The Phoenix
Contact PSM-ME repeater/isolator was removed from
Test 2
The second test measured the noise on the active net-
work with the Phoenix Contact PSM-ME isolator installed
in the network. The following screen capture from the
Figure B-28. Network Noise with Phoenix Contact PSM-ME Isolator
B - 50
the circuit and the USB/RS485 convertor was wired di-
rectly to the Vission 20/20 RS485 serial port. The follow-
ing screen capture from the scope shows the amount of
noise on the network signals, see Figure B-27.
Figure B-27. Network Noise
scope shows the amount of noise on the network signals.
The noise on the signal lines has been signifi cantly re-
duced with the addition of the Phoenix Contact PSM-ME
isolator installed in the network.
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 2.0