Campbell Scientific CR9000X Measurement and Control System - Manual (Page 42)

Overview
CR9052DC Anti-Alias Filter Module with DC Excitation
CR9052DC MADE IN USA
CR9052EC
FILTER MODULE CONNECTOR DC EXCITATION MADE IN USA
FIGURE OV1-7. CR9052DC with CR9052EC
The CR9052DC is a high-performance Fast Fourier Transform (FFT) spectrum
analyzer and anti-alias Finite Impulse Response filter module. Each
CR9052DC includes one CR9052EC. Additional CR9052ECs can be
purchased separately. The CR9052DC typically remains in the CR9000(X)
chassis while each CR9052EC remains connected to sensors. This allows one
CR9000(X) system to be moved from location to location and be quickly
connected to the sensors on-site.
The module includes six anti-aliased, differential analog measurement
channels, each channel having its own programmable gain amplifier, pre-
sampling analog filter, and 16 bit sigma-delta analog to digital converter. \
The Differential channels cannot be configured as two Single
Ended inputs. NOTE
The CR9052DC can burst measurements to its on-board, 8-million sample
buffer at 50,000 measurements per second per channel. Using the FFT
spectrum analyzer mode, the module's DSP can provide real-time spectra from
"seamless", anti-aliased, 50-kHz, 2048-point time-series snapshots for each of
its six analog input channels. The decimated data can be downloaded to an
appropriate PC card at an aggregate rate of 300,000 measurements per second.
It has differential input ranges from ±20 mV to ±5 V and operational input
voltage limits of -5 to +15 VDC. Inputs outside of this range will return either
erroneous measurements or NAN.
Inputs outside of the range of -40VDC to +50VDC can compromise the
integrity of the measurements for all of the inputs on this and other modules in
the CR9000X chassis, as well as possibly damaging the system and creating
communication problems between the logger and PC.
Each input channel has both regulated constant voltage excitation (VEX) and
regulated constant current excitation (IEX) channels. These can be used for
ratiometric bridge measurements. The corresponding Current Return (IRTN)
or Voltage Return (VRTN) must be used for the input of the ground side of
OV-10