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Introduction
The digitizer is useful for low frequency, high voltage waveform analysis. This document is intended as a example of using
the HP3070 digitizer to measure an analog waveform. The digitizer sample interval may be set from 25us to 32.3ms and has an
input voltage range of +160VDC to –160VDC. The full specifications for the digitizer are available in the HP3070
Series 3 Users' Documentation in the section titled "Test Methods: Analog", sub-section "Analog Functional
and Mixed Testing".
A graphic representation of the input/output signals for this test are shown on Page 4 of this document.
This test example is the test for one of three outputs from a three phase motor driver. The output of the motor driver,
"PHASE_OUT" is controlled by the three phase inputs defined as "PHASE_IN".
Digital Test Description
The digital portion of the test is pretty standard stuff. The notable items defined in the digital test are the vector cycle,
which is set to 50us, and the use of the "trigger digitizer" function.
The vector cycle timing is important in this example since after the initial trigger is issued from the digital subsystem,
all digitizer measurements are taken at a 150us sample rate. The digital vectors consist of eight vectors defining 1 of 8
possible phase combination inputs and a vector named "Keep" that simply retains the previous digital input states.
Each set of digital input changes are followed by two "Keep" vectors, yielding a digital input pattern rate of 150us.
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Digital Portion of the Mixed Test
!IPG: rev B.02.06 Mon Dec 02 11:11:16 1996 vector cycle 50ureceive delay 49u
default device "11.5"
assign PHASE_IN to nodes "FESENPA_IN","FESENPB_IN","FESENPC_IN"
family TTL
inputs PHASE_IN
!***************************************
vector Keep
set PHASE_IN to "kkk"
end vector
vector PHASE_000
set PHASE_IN to "000"
end vector
vector PHASE_001
set PHASE_IN to "001"
end vector
vector PHASE_010
set PHASE_IN to "010"
end vector
vector PHASE_011
set PHASE_IN to "011"
end vector
vector PHASE_100
set PHASE_IN to "100"
end vector
vector PHASE_101
set PHASE_IN to "101"
end vector
vector PHASE_110
set PHASE_IN to "110"
end vector
vector PHASE_111
set PHASE_IN to "111"
end vector
!***********************
unit"TEST"
execute Phase_000
continue analog
execute Phase_100
execute Keep sync trigger digitizer
execute Keep
execute Keep ! Sample t1
execute Phase_110
execute Keep
execute Keep ! Sample t2
execute Phase_111
execute Keep
execute Keep ! Sample t3
execute Phase_011
execute Keep
execute Keep ! Sample t4
execute Phase_001
execute Keep
execute Keep ! Sample t5
execute Phase_000
execute Keep
execute Keep ! Sample t6
execute Phase_100
execute Keep
execute Keep ! Sample t7
execute Phase_110
execute Keep
execute Keep ! Sample t8
execute Phase_111
execute Keep
execute Keep ! Sample t9
execute Phase_011
execute Keep
execute Keep ! Sample t10
execute Phase_001
execute Keep
execute Keep ! Sample t11
execute Phase_000
execute Keep
execute Keep ! Sample t12
continue analog
end unit
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Analog Test Description
The most interesting aspect of the analog subtest is the data array. The first data array, named "PHA_Hi", defines
the upper limit for each measurement sample, while the second array, named "PHA_Lo" defines the lower limit for
each measurement sample. Positioning of the values in the data arrays are critical. The first element of each array is used
to check the first measurement, the second the second measurement, etc. In the following example the first measurement of
the array is defined to have a maximum value of 37V and a minimum value of 35V, while the second measurement range is 19V-17V.
data "PHA_Hi"
values 37, 19, 1, 1, 19, 37, 37, 19, 1, 1, 19, 37
end data
data "PHA_Lo"
values 35, 17, -1, -1, 17, 35, 35, 17, -1, -1, 17, 35
end data
The digitizer is set up to take 12 measurements at a 150us rate after triggered from the digital subsystem. An error will
occur if the number of samples to be taken exceed the number of measurements contained in the data array.
detector digitizer,samples 12,digital,interval 150u, timeout 9,expect 40
After the digitizer is set up, the analog subsystem returns control to the digital subsystem and waits for a trigger.
continue digital
Upon return from the digital subsystem, the measurements sampled are compared to the data array.
measure "PHA_Hi","PHA_Lo"
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Analog Portion of the Mixed Test
!IPG: rev B.02.06 Mon Dec 02 11:11:15 1996
test powered mixed
data "PHA_Hi"
values 37, 19, 1, 1, 19, 37, 37, 19, 1, 1, 19, 37
end data
data "PHA_Lo"
values 35, 17, -1, -1, 17, 35, 35, 17, -1, -1, 17, 35
end data
test "PHA"
continue digital
end test
subtest "PHA"
connect i to nodes "PHASE_OUT"
connect l to "GND"
detector digitizer,samples 12,digital,interval 150u, timeout 9,expect 40
continue digital
measure "PHA_Hi","PHA_Lo"
disconnect all
end subtest
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Input & Output Waveforms
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