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APE1553-1/2(-DS) Hardware Manual
4.1.1 MILScope PBI section
The MILScope part on the PBI has two main tasks, the first one is the coupling of the Analogue
to Digital Converter inputs to different sources, and the second is the conversion from the
analogue input signals to digital values.
A relay circuitry is used to couple the input of the A/D-Converter to different sources and
voltage ranges. The following table shows the available coupling modes:
•
Extern
3V
SS
30V
SS
•
Stub
3V
SS
30V
SS
•
Other
Primary to Secondary
(used for 100MSample Mode)
Secondary to Primary
(used for 100MSample Mode)
The following figure shows the principal of the different coupling modes.
Figure 4.2-2: MilScope coupling modes
Primary Channel
Secondary Channel
measurement
range
3V
SS
30V
SS
Coupling
Stub
Extern
TP
measurement
range
3V
SS
30V
SS
Coupling
Stub
Extern
TP
ADC
ADC
K1
K4
K2
K5
K3
K6
The A/DC has a resolution of 10Bit, therefore a LSB in the 30V
SS
measurement range
represents:
SS
SS
LSB
mV
V
V
30
2
30
10
≈
=
Whereas a LSB in the 3V
SS
measurement range represents:
SS
SS
LSB
mV
V
V
3
2
3
10
≈
=
It is possible to delay the sample point of the A/DC channel B by a half clock cycle. This allows
in the coupling mode “other” (Primary to Secondary/ Secondary to Primary) a sampling rate of
100MSamples.
4.1.2 MILScope Mainboard section
The data output of the A/D-Converter is provided to the FPGA for a first data analysis. All
control functions for the A/DC and the coupling circuitry are implemented in the FPGA as well.
Different sampling rates can be used, (100MSamples 1 bus, 50MSamples 2 busses down to
195KSamples).