Measurement Computing DBK45 - Manual

DBK45
4-Channel SSH and Low-Pass Filter Card
Overview …… 1
Hardware Setup …… 2
Card Connection …… 2
Card Configuration …… 2
Configuring DBK45 Filter Sections …… 3
DaqBook/100 Series & /200 Series and DaqBoard [ISA type] Configuration …… 5
DaqBook/2000 Series and DaqBoard/2000 Series Configuration …… 5
Software Setup …… 5
DBK45 – Specifications …… 6
Reference Notes:
o Chapter 2 includes pinouts for P1, P2, P3, and P4. Refer to pinouts applicable to your
system, as needed.
o In regard to calculating system power requirements, refer to DBK Basics located near
the front of this manual.
Overview
The DBK45 combines the features of the DBK17 (SSH) and the DBK18 (low-pass filter) cards. Each
DBK45 provides 4 input channels to a LogBook or Daq device system. Each of the main 16 analog input
channels can accept four DBK45s, for a maximum of 64 DBK45s and 256 analog input channels. The
simultaneous sample-hold function is activated at the beginning of each channel scan and freezes all
signals present on DBK45 inputs for the duration of the scan, allowing for non-skewed readings of all
channels.
You should never set a DBK45 channel as the 1st channel in a scan due to timing of
the SSH line.
For each of the four channels, a separate filter and a sample-hold stage follow the input stage. The outputs
are connected to a 4-channel multiplexer stage. The enabled-output MUX allows four DBK45s to share a
common analog input channel.
The DBK45 has an instrumentation amplifier for each channel, with switch-selected gains of ×1, ×10,
×100, ×200 and ×500. A socket is provided for a gain resistor for custom gain-selection instead of the 5
factory-default gains. Gain for any channel can be set to any value between unity and ×500 by installing
an appropriate resistor. Four separate filter stages follow the 4 input stages. The outputs are connected to
a
4-channel multiplexer stage. The enabled output MUX allows four DBK45s to share a common analog
base channel.
Input can be connected to a channel’s BNC or terminal block connector. The differential inputs are
provided with switchable 100 k
Ω bias resistors to analog common.
DBK Option Cards and Modules 987696 DBK45, pg. 1