eDAQ PowerChrom 280, Руководство пользователя

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14 PowerChrom
assembles groups of data points into ‘packets’ and then transmits them
via the USB connection to the computer, where the PowerChrom
program receives, records, and displays the data.
A 16-bit DAC (digital-to-analog convertor) is used to control the analog
output of the recording unit available through the Instrument Connection
port,
Figure 1–3, page 7 . The DAC produces waveforms under
software control that are fed through an attenuation network to produce
different full-scale ranges. The signal is then buffered by an amplifier to
give it the capability to drive external loads.
The injection signal input is coupled to the recording unit via an optical
switch providing high voltage isolation,
Figure 2–6 .
Back
Panel
16-bit ADC
Clock
30 MHz
Injection signal
50/60Hz
Interrupt
Multiplexer
2 Programmable
Gain Amplifiers
16-bit DAC
Range
Control
+1
Instrument Interface
USB Port
IEC Mains Input
Switching
Power
Supply
Links to set
Contact Closure
or TTL
System
Glue Chip
PPC403 CPU
Anti-alias filters
Instrument Connection Port
DRAM
Flash
ROM
USB
Controller
Figure 2–4
Block diagram of the
PowerChrom 280 unit.