Measurement DBK42 User Manual

DBK42 16-Slot 5B Signal Conditioning Module

Overview …… 1
Hardware Setup …… 2

DBK42 Connection …… 2
DBK42 Configuration …… 2
5B Module Connection …… 2
Power Considerations …… 2
Terminal Block Connections …… 3
DaqBoard/2000 Series and cPCI DaqBoard/2000c Series Connections …… 5
DaqBook/100 Series & /200 Series and ISA-Type DaqBoard Configuration …… 5
DaqBook/2000 Series and DaqBoard/2000 Series Configuration …… 5

Software Setup …… 6
DBK42 – Specifications …… 8

Reference Notes:

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

Overview

The DBK42 allows LogBook or Daq device systems to work with up to 16 5B signal conditioning
modules. Modules are available for various signal types (e.g., low-level thermocouple signals, strain-gage
signals, etc). The DBK42 offers 500 V isolation from the system and between channels. The DBK42 is
compatible with all 5B output modules, and the configuration is very flexible. You can select the type of
signal attached to each channel.

system, as needed.

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

the front of this manual.

An accessory cable connects the DBK42’s output to the P1 analog input connector. One LogBook or Daq
device can support up to 16 DBK42 units with a maximum of 256 isolated analog input channels. The

LogBook or Daq device scans the DBK42 channels at the same 10 µs/channel rate as other DBKs (256
scans in 2.56 ms in a full system).

The DBK42 can obtain power from an included AC adapter, an optional DBK30A rechargeable battery
module, or directly from a 12 VDC source (such as a car battery). The built-in power supply can serve a
fully-configured system using bridge excitation.

For DaqBoard/2000 Series applications, DBK42 is typically powered from an included AC adapter. The
unit’s built in power supply can serve a fully-configured system using bridge excitation.

DBK Option Cards and Module 967694 DBK42, pg. 1

Each terminal block contains 4 terminals (per channel) for access to input and excitation features of 5B
modules.

The optional CN-71 and CN-72 signal connection blocks provide a convenient way of connecting analog
signals to the DBK42.

• The CN-71 is for non-thermocouple use.

• The CN-72 (with cold junction sensors) is for thermocouple use. The CN-72 has a clear

Hardware Setup

DBK42 Connection

The DBK42 has screw-terminal connectors for easy access to the analog inputs. 2-wire and 4-wire
hookups are shown later in this section.

Note: Analog channels are isolated from each other, and no analog ground is provided.

DBK42 Configuration

Up to 16 DBK42s can connect to a LogBook or a Daq device. As a daisy-chain interface,
each module must appear unique and use a different channel.

To configure the module, locate the 16×2-pin header (JP1) near the front of the DBK42
board. Note the 16 jumper locations labeled CH0 through CH15 representing the base
Analog Input Channels. Place the jumper on the channel you wish to use.

plastic shield over its screw terminals to protect you from high voltage on the input terminals.

Only one jumper is used on a single DBK42. No two cards in a system
can use the same JP1 setting.

5B Module Connection

Each input of the DBK42 is processed through a user-installed 5B signal-conditioning module. Different
5B modules are used with different transducer and signal sources. To install the modules:

1. Match the footprint of the module with the footprint on the circuit board (see figure).

2. Gently place the module into the footprint, and screw it down.

3. When installing current input modules (SC-5B32 series), install the supplied current-sense resistor

(SC-AC-1362) in the resistor footprint adjacent to the module mounting footprint.

4. Record the module’s channel number; label all units and connectors for identification.

Power Considerations

The DBK42 has an internal, isolated switching-type power supply that operates on 10-20 VDC at varying
input currents depending on the input voltage and 5B-module loading. The power drain at a given output
load is constant; input current will vary inversely with the input voltage.

DBK42, pg. 2 967694 DBK Option Cards and Modules

A DBK42 populated with strain-gage modules will draw more current than with other types of input
modules. The table shows the DC input requirements for the worst-case setup (with 16 strain-gage
modules or 16 thermocouple modules).

Input Volts

With Strain-Gage Modules With Thermocouple Modules

10 VDC 3.0 A 0.60 A
11 VDC 2.7 A 0.54 A
12 VDC 2.4 A 0.48 A
13 VDC 2.2 A 0.44 A
14 VDC 2.0 A 0.40 A
15 VDC 1.9 A 0.38 A
16 VDC 1.8 A 0.36 A
17 VDC 1.7 A 0.34 A
18 VDC 1.6 A 0.32 A
19 VDC 1.5 A 0.30 A
20 VDC 1.4 A 0.28 A

Input Amperes

Power sources include:

• The standard TR-25 AC plug-in power pack (provided with the DBK42) can supply 900 mA at

15 VDC. The optional TR-40U can supply 2700 mA at 15 VDC.

• The DBK30A battery pack can supply power for a typical DBK42 configuration; however, in a

fully-populated strain-gage configuration, the battery run-time will be limited to about 1½ hours.

• A 12 V lead-acid gel-cell type battery can easily power a fully-populated strain-gage

configuration. The battery drain will be about 2.4 A-hr; battery size should be considered for
systems with long run-times. (For example, a common-size 5.0 A-hr battery will operate for
about 2 hours). A typical automotive 12-V lead-acid battery (e.g., 60 A-hr) can easily power a
DBK42 for long run-times (about 24 hours).

The input fuse is a 4-A Slo-Blo 1-1/4" × 1/4" glass-type such as Littelfuse 313004 or Bussman MDL-4.

Terminal Block Connection

Input signals (and excitation leads) must be wired to the DBK42 signal termination panel. Sixteen
4-terminal blocks accept up to 16 inputs. These connectors are located on a removable PC board that plugs
into two DIN96 rectangular connectors on the rear panel.

Terminal blocks are connected internally to their corresponding signal conditioning module. The terminal
blocks accept up to 14-gage wire into quick-connect screw terminals. Terminals on each block are
numbered 1 through 4. Each type of input signal or transducer (such as a thermocouple or strain gage)
should be wired to its terminal block as shown in the figure. Wiring is shown for RTDs, thermocouples,
20 mA circuits, mV/V connections, and for full- and half-bridge strain gages.

DBK Option Cards and Module 967694 DBK42, pg. 3