Measurement DBK50 User Manual

DBK50 and DBK51 8-Channel Isolated Voltage Input Modules

Overview …… 1

Input Attenuation/Gain Factors …… 2

Hardware Setup …… 2

Signal-to-Module Connection …… 2
Module Configuration …… 2
DaqBook/100 Series & /200 Series and DaqBoard [ISA type] Configuration …… 3
DaqBook/2000 Series and DaqBoard/2000 Series Configuration …… 4

Software Setup …… 4
DBK50 and DBK51 – Specifications …… 4

Reference Notes:

o Chapter 2 includes pinouts for P1, P2, P3, and P4. Refer to pinouts applicable to your

Overview

system, as needed.

o In regard to calculating system power requirements, refer to DBK Basics located near

the front of this manual.

Except for their ranges, the DBK50 (high-voltage) and the DBK51 (low-voltage) are identical. Both have
eight channels isolated from themselves (750 V) and from the LogBook or Daq Device analog common
(1250 V). Each channel’s input impedance is over 10 M
measured. Voltages can be read from DC to more than 20 kHz. One of three voltage ranges can be chosen
via software:

• for DBK50: ±10 V, ±100 V, or ±300 V.

• for DBK51: ±100 mV, ±1 V, or ±10 V.

Ω to minimize loading of the circuit being

With standard plug-in attenuator assemblies, the voltage ranges are interch angeable. The gain or
attenuation factor depends on the range, but the full-scale output for any range is +5 V.

Note: A fourth “range” delivers a shorted input voltage reading to allow offset compensation in some

applications.

DBK Option Cards and Modules 989594 DBK50 and DBK51, pg. 1

Input Attenuation/Gain Factors

Gain and attenuation may be calculated using the formula:

where: K is the attenuation or gain factor (the values of K for

available voltage ranges are given in the table).

Vin is the voltage applied to the module input channel.
Vout is the amplified or attenuated voltage from the module

output back to the main unit.

Hardware Setup

Signal-to-Module Connection

The DBK50/51 rear panel has 8 plug-in screw terminals for easy access to the 8 analog input channels.
There is a high (right side) and a low (left side) terminal in each pair to maintain consistent polarity (see
figure). For AC signals, the polarity is arbitrary unless multiple signals must maintain their phase
relationship.

K = Vin / Vout

Input Range Function K

300 V Range Attenuates 60
100 V Range Attenuates 20

10 V Range Attenuates 2

1 V Range Amplifies 0.2

100 mV Range Amplifies 0.02

Note: not all input ranges are

available on a single unit.

Module Configuration

Factory Default: Low-pass filter – Enabled

Several jumpers must be set on the DBK50 and DBK51 to match your application:

• 2 jumpers on JP1A or JP1B to select the main channel to use (see following figure).

• 1 jumper on JP1C for upper or lower sub channels

• 1 jumper on JPn02 to use or bypass the low-pass filter—one for each channel number (n)

The main output channel is one of the 16 primary data acquisition device [LogBook or Daq device]
channels. Each DBK50 [and DBK51] has 8 input channels and can be set to an upper or lower sub­channel that allows 2 modules to share a single LogBook or Daq device channel. Thus, a fully-populated
system can have 256 input channels.

After determining a main channel number for the module, set two jumpers on JP1A or JP1B for the desired
channel. The two jumpers must be used side-by-side on the selected channel. This is illustrated for
channel 0 in the following figure. Next, set the JP1C jumper for the eight upper or eight lower sub­channels. Note that two modules may share the same main channel if one is set to the upper sub channel
and the other set to the lower sub channel.

Each of the 8 input channels has a 3-pole low-pass filter that may be manually selected or bypassed by
positioning 2 shunt jumpers on 2×2 headers for each channel. Orient the jumpers parallel/horizontal
(enable) or perpendicular/vertical (bypass) to the header label (JP102 to JP802 for each of 8 channels).
The following figure can be used for orientation.

DBK50 and DBK51, pg. 2 989594 DBK Option Cards and Modules