Cooper Instruments DFI-7000 Installation Manual

DFI 7000 DIGITAL FORCE INDICATOR USER’S GUIDE

1.0 INTRODUCTION

The DFI 7000 Signal Conditioner-Indicator is a complete 4-1/2-digit signal conditioner and indicator housed in a 1/8
DIN case. This unit provides many of the features found on expensive, larger signal conditioning units.

• Full 20,000 count resolution

• Accepts strain-gage transducer inputs from 0.5 to 50 mv/v

• 0-5V output

• +/-0.03% accuracy

• Screw-type power and I/O connectors

• Shunt calibration from front-panel

• 1/8 DIN “panel meter size” case

• 5- or 10-volt transducer excitation

• Optional Dual Limits

• Optional Peak Detector

• Optional Track-and-Hold

• 110- or 220-V Power

2.0 DESCRIPTION

2.1 Configuration

Within the DFI 7000’s enclosure there are three printed circuit boards (four if an option is selected). The Main
Board contains the circuitry for the power supply and A/D converter. The Display Board contains all circuitry
needed to drive the LED display and the units display bar. The Signal Conditioner Board contains circuitry for the
signal amplifier and for the excitation power supply.

The Display Board solders to the main Board, whereas the Signal Conditioner plugs into it. If the Dual Limits, Peak
Detector or Track-and-Hold option is supplied, a fourth plug-in board houses it. DUE TO SPACE CONSTRAINTS,
ONLY ONE OPTION CAN BE INSTALLED ON A PARTICULAR UNIT. Adjustments for COARSE SPAN, COARSE
ZERO, FINE ZERO, and SCALING are provided. FINE ZERO and FINE SPAN may be adjusted from the front
panel without removing the front bezel. The entire unit may be quickly panel- or rack-mounted with the snap-on
attachments supplied with every unit.

2.2 Specifications

GENERAL

# Channels 1
Case Material Noryl Plastic
Temperature Storage
Temperature Operating

TRANSDUCER INTERFACE

Transducer Excitation 5 or 10 VDC
Type of inputs accepted 0.5 mv/v to 5.0 mv/v or 5 mv/v to 50 mv/v
Transducer Current drive (ma.) 50
Input Gain Range 10-1000
Push Button Shunt Cal Yes
Calibration Method Manual (front panel)
Zero Balance +/- 15% F.S. Min.
Noise & Ripple <100 microvolts
Transducer Minimum Impedance 350Ω (10v Exc.)

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-20° F to 200° F
32° F to 130° F

AMPLIFIER CHARACTERISTICS

Full-Scale Output 5 Volts
Output Impedance <2 ohms
Accuracy +/-0.03%
Frequency Response >100 Hz.
Common Mode Rejection >80%
Fine Span Adjust +/-15%
Coarse Zero Adjust >80%
Short Circuit Protected Yes

DIGITAL DISPLAY CHARACTERISTICS

# Characters Displayed 4-1/2
Conversions per second 3
Scaling 0-19999
Scaling Method Potentiometer
Polarity Indication "-" for Negative
Decimal Pt. Selection Jumper (non-solder)
Display Size 0.56”
Overrange Indication Flashing display
Resolution 1/20000
Type LED

PHYSICAL CHARACTERISTICS

Input/Output Connector Screw Terminals
Weight 2 lbs.
Mounting Bench, panel or rack
DIN Size 1/8 DIN

POWER SUPPLY

Power Requirements 115VAC/220VAC (factory set, field changeable)

FRONT PANEL

Digital Display 4-1/2 digits LED
Limit Condition LEDs

3.0 UNPACKING, INSTALLING AND WIRING

The DFI 7000 is shipped in a single container. Inspect the unit for shipping damage, and gently shake and listen
for loose components prior to energizing it. Report shipment damage to the carrier; it is his responsibility to safely
transport the unit. If there is transportation damage and you have difficulty getting the problem resolved, contact
Cooper at [phone]. We will attempt to assist in resolving the situation.

3.1 Selecting Excitation Voltage

The DFI 7000 provides a 5 or 10 VDC strain-gage transducer power supply. These units are normally set for 10
VDC at the factory. To check or change the excitation voltage, proceed as follows:

1. Remove the bezel and front panel with a small screwdriver.

2. Carefully pull the Main Board out of the unit. All boards will come out simultaneously.

3. Gently remove the vertical Signal Conditioner Board from the right edge of the Main Board and locate the two
sets of three standoffs at the left end of this board. Check the jumper location for excitation voltage setup.

5 Volt Excitation10 Volt Excitation

4. Replace the Signal Conditioner Board onto the Main Board and slide the board assembly into the case.

5. Reinstall the front panel and bezel.

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3.2 Mounting the Unit

For panel mounting, cut a rectangular hole 3.58” in width by 1.73” in height. Remove the panel mounting brackets
by unsnapping them from the sides of the DFI 7000. Place the DFI 7000 through the panel cutout and reattach the
panel mounting brackets to the sides of the case. Use a small screwdriver to tighten the panel mounting bracket
adjusting screws until the case is pulled tightly into the panel.

3.3 Wiring to The Sensor

All connections to the DFI 7000 are made through the rear-panel 15-pin connector. Terminal 1 is AC HI; terminal
15 is + EXC. This connector may be separated from the DFI for wiring by pulling on it gently. Connect the strain­gage sensor to the DFI 7000’s last four terminals, marked (+) EXC.,(-) EXC., (+) SIGNAL and (-) SIGNAL terminals,
respectively.

The DFI 7000 will accept strain-gage transducers with bridge impedances of 350 ohms or greater. Wires from the
transducer may be pushed into the terminal using a small screwdriver.

CAUTION: The connector can be inserted incorrectly. Fluted side down. Flat side is up! Incorrect insertion of this
connector will result in extreme circuit damage.

3.4 Wiring The Output

If the 0-5V output of the DFI 7000 is to be used, wire to terminals 10 and 11, marked +OUTPUT and –OUTPUT.
Observe the correct polarity.

3.5 Wiring To The Optional Limits

The DFI 7000 utilizes relay output limits that are energized when the signal level exceeds the limit setting. The
COMMON, NORMALY OPEN, and NORMALLY CLOSED contacts for the L1 limit set are on terminals 4, 5 and 6
respectively and for the L2 limit set on terminals 7, 9 and 8. The relays are rated at 24 volts, 1.0 amp (non­inductive) or 48V, 0.5 amp (non-inductive).

NO

NC

COM

LIMIT ONE (L1)

LIMIT TWO (L2)

NO
NC

COM

3.6 Wiring To The Optional Peak Detector

The DFI 7000 is available with an optional peak detector module. This circuit will detect the highest positive value,
which has been attained since the peak detector was last reset. Reset may be accomplished by pressing the RST

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