4-40 ChartView Software Reference ChartScan User’s Manual
• When using Burst Mode, data saved to disk can still be viewed in PostView. However, the PostView
chart setup will only allow you to select the single channel (previously selected in ChartView as the
high-speed Burst Mode channel).
Example: If Channel 4 is selected as the High-Speed Setup Channel (in ChartView’s Acquisition Setup),
and data is acquired and saved to disk, then the only channel that can be selected for PostView’s
chart display is Channel 4.
• When you switch operation from Burst Mode, back to Normal Mode…
a) channels that were assigned to Charts will automatically re-enable, i.e., returned to an ON state.
b) channels that were not assigned to Charts, but were set to ON prior to selecting Burst Mode, will not
return to the ON state automatically.
c) the channel that was selected for Burst Mode will remain in the ON state, unless turned off by the user.

Measuring AC Voltage, or AC RMS Voltage

Introduction
When someone talks about measuring AC voltage, they are usually talking about measuring
“AC RMS,” which is the effective periodic value of the voltage for one full cycle. RMS (Root Mean
Square) is the square root of the average of the squares of the signal being measured.
ChartScan, MultiScan and NetScan can use multiple channels to measure AC RMS voltages; but are
restricted to the use of one channel when measure actual AC voltage at 60 cycles. The following
questions and answers should help to clarify this point.
Question 1: Can I measure multiple channels of 60 cycle waveforms with ChartScan, MultiScan, or
NetScan?
Answer: No. Measuring a 60 cycle (or 50 cycle) waveform with ChartScan, MultiScan, or
NetScan requires the use of High-speed, single-channel Burst Mode. While in this mode,
only one channel can be measured. See related questions 2 and 3.
Question 2: How do I measure a 60 cycle waveform using just one channel?
Answer: To measure AC, you must sample at a rate fast enough to see every cycle line.
Multiplying the number of cycles by 10 will provide an adequate sampling rate. For
example: for 60 Hz you should sample at 600 samples/sec; and for 50 Hz you should
sample at 500 samples/sec.
To obtain these sample rates [with ChartScan, MultiScan, or NetScan], use the
High-speed, single-channel (Burst Mode).
Question 3: Can I measure multiple channels of 60 cycle “AC RMS” voltage with ChartScan,
MultiScan, or NetScan?
Answer: Yes, providing the amplitude of the signals falls within the range of the card. For
example, if your amplitude was 120V you would need to use a high voltage signal-
conditioning card. Note that the CSN14/HV/S card has a high range of ±250V. To
measure multiple channels of 60 cycle AC RMS (or 50 Hz, AC RMS in Europe), perform
the steps in the following section, Measuring AC RMS.