TDS420 - Measurement all channel Amplitude using Measurement channels

[Muthuraman]

Hi,

I am using TDS420 digital scope. The requirement is simple. To measure the amplitude of allt he 3 channels. Right now since we dont have the UUT, we are only trying to validate the TDS420 driver part. So, all 4 channels are not connect to any signal. I am using LabVIEW 2011 and using SCPI command to read the 4 measurement channels (Each measurement channel configured to measure amplitude of each channel).

But only measurement channel 1 returns some meaningful 0.4 V. Other measurement channels are returning some 9.9E37 (invalid) value and also is returning some invalid unit (Sec, C,etc).

I have attached the test program in this link along with the observed result as screenshot.

Please advice

Regards,

Muthuraman

[crossrulz]

Are the measurements on the scope screen correct?  Here are some ideas from my experience with a different Tek scope:

1. Turn on the measurements before setting them up
2. Add a delay after acquiring the waveform before reading the measurement results.  It takes the scope time to calculate those measurements.

[Wayne.C]

TDS420 has a spot (Probe Comp?)on the front panel that puts out a nice square wave.  Hook your scope probes up to this source and perform various measurements.