Table 9.2-1 - Acquisition Array - Newport ESP6000 User Manual

Section 9 — Advanced Capabilities
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ADC gain and polarity parameters are software-selectable from either API
function calls or through the ESP-util.exe Windows setup utility. Gain
settings are 1.25, 2.5, 5.0. or 10.0 volts. Users can select either uni-polar
(0 to +) or bi-polar (- to +) polarity (range).
First the Input-Multiplexer (MUX) automatically selects one of the eight (8)
analog voltage inputs based on the API function call channel parameter.
The signal then passes to the Programmable Gain Instrumentation Ampli-
fier (PGIA), which must be pre-set to accept a designated voltage range.
The amplified signal is routed through the anti-alias filter, which filters out
frequency input over 50 KHz (default). The (16-bit resolution) signal is
then converted into digital form for processing by the Digital Signal
Processor (DSP).
The converter can read from one to eight samples/channels, one-at-a-time,
during a servo cycle (about 400 milliseconds). Sampling is not instanta-
neous, but occurs with a slight delay between each sample. Sampling for
any one channel can be in one of two modes: (1) instantaneous (when an
application is executing), or (2) at a designated interval. N samples can be
obtained at an interval of m number of clock cycles. A typical acquisition
sampling array is shown in Table 9.2-1.
Table 9.2-1 — Acquisition Array
first
element
Ch1 Ch3 Ch8
Ch xx = value read at analog channel number xx
Axis xx = position value for axis xx
CLK = servo clock counter
Axis 2 Axis 4 Axis 7
last
element
CLK
9 - 3