Rockwell Automation 1757-FFLD Linking Device Configuration Manual - Manual (Page 27)

Publication 1757-PM002A-EN-E - June 2006
Set Up A System 2-17
Another way of testing the signal quality of a network is to use an oscilloscope.
We recommend a hand-held battery-operated unit because of its small size and
ease of use. The Fluke 199-3 ScopeMeter is one such scope.
Figure 2.9 Fluke 199-3 200MHz ScopeMeter
Other scopes that can be used include the TPI-E1505, the Extech-381275
(
www.professionalequipment.com ), and the Techtronix THS700 Series
( www.tek.com ).
Signal Analysis
Oscilloscopes, whether portable or stationary, from 50MHz to 1GHz, can be
used to capture and examine the waveform. The power supply waveform
should be a +/- 0.75 VDC to +/- 1.00 VDC square wave riding on the 9 V
DC to 32 V DC steady power supply with < 0.10 V DC ripple. The sharper
the rising and falling edges of the waveform, the better the data transfer. The
physical media of a system will determine what shape the waveform takes.
The signal is a current modulated ±10mA signal on a 50 test load. This
generates a 1.0 Vpp signal. A valid signal can range from 150mVpp up to
1.0Vpp and noise must not exceed 75mvpp (Figure 2.10).