Cooper DFI 200 User Manual

DFI 200 HAND HELD INDICATOR OPERATION MANUAL

1 INTRODUCTION

This manual contains information for the operation of the DFI 200 hand held load cell monitor. The DFI 200 is
suitable for measuring weight, pressure, force, torque etc. The input required by the DFI 200 is a 4 wire mV/V
output type transducer. 5V excitation is provided for the transducer. Calibration, and set up functions are easily
achieved via front pushbuttons.

The DFI 200 is a high accuracy meter with the capability of high speed sampling. Sample rate is programmable in
steps from 5 to 100 samples per second. The instrument has a full scale range of 0.5mV/V to 100mV/V. Up to 3
separate calibration sets can be stored internally allowing viewing of scaling for up to 3 different load cells, or 3
scaling ranges without the need to recalibrate each time.

When used with the external memory option the DFI 200 can “read” the calibration scaling values stored in memory
in the load cell connector shell. The instrument can then display the correct scaling value for each individual load
cell which uses a memory device without the need for recalibration.

The DFI 200 is supplied with RS232 communications as standard but by default this is disabled. See “Serial
communications” chapter for internal DIP switch settings required for enabling the serial communications.

The DFI 200 has three calibration/scaling method options. It may be calibrated by applying two known weights to
the load cell or by entering the mV/V value for the load cell or via a single offset value.

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2 ELECTRICAL CONNECTIONS

Power for the DFI 200 is provided by a 9VDC (216) battery. The battery cover is located at the underside of the
case. External connections to the DFI 200 are made via a 9 pin “D” male connector. The DFI 200 provides 5VDC
excitation for the mV/V output transducer. Electrical connections are as shown below.

Refer to ”External memory” chapter for details of the optional external memory chip. Refer to ”Serial
Communications” chapter for details of the RS232 wiring connections.

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3 FUNCTION TABLES – SUMMARY OF SETUP FUNCTIONS

Functions in this first table are available in FUNC or CAL mode.

Display Function Range Default Your record Ref

Calibration memory selection
Display rounding
Memory chip address
Decimal point place
Digital filter to

Functions in this second table are available only in CAL mode.

Display

Function Range Default Your

mV/V input range

Sample rate in samples/sec.

, , or
to
to

to

record

4.6

4.7

4.1

4.2

4.3

4.4

Ref

4.5

User pushbutton function

Live input calibration first point Any display

Second point for live input
calibration

Alternative mV/V calibration
method

Calibration offset Any display

Zero range limit

Zero reference n/a n/a 4.14

Display zero n/a n/a 4.15

Clear zero n/a n/a 4.16

Power off time

Baud rate for serial
communications

Parity for serial input

Output for serial communications

Instrument address for serial
communications

value
Any display
value

value

n/a 4.9

n/a 4.10

n/a 4.12

4.8

4.11

4.13

4.17

4.18

4.19

4.20

4.21

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4 EXPLANATION OF FUNCTIONS

The DFI 200 setup and calibration functions are configured through a push button sequence.

Two levels of access are provided for setting up and calibrating namely:

•
rounding, decimal point and digital filter settings only.

•
calibration parameters.

Once or mode has been entered you can step through the functions, by pressing and releasing the F
push button, until the required function is reached. Changes to functions are made by pressing the ^ or v push
button (in some cases both simultaneously) when the required function is reached. Any changes to a function will
not be saved until the F button is pressed to accept the change.

mode (simple push button sequence) allows access to calibration channel selection, display

mode (power up sequence plus push button sequence) allows access to all functions including

4.1 Calibration internal memory selection

Display:
Range: CH1,

Default Value: CH1

Selects one of the three possible calibration internal memories (CH1,
external memory chip is used - see chapter 4.24). The function allows the instrument to be calibrated to up
to 3 different load cells and hold the calibration values in internal memory. Alternatively 3 different calibration

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, or

, , also if the optional

scaling values may be entered for a single cell, allowing the same cell to display in different units e.g. Kilonewtons,
Kilograms and Tons. The user may select the load cell to be used via this function or via the User

pushbutton if the pushbutton has been programmed for this purpose (see
independent calibration memories you may use either the

the
calibration method best suits the application.

The channel selected will always default to
to independent calibration scalings for each channel selected each channel can be assigned different decimal point

(

), digital filter ( ), mV/V input range ( ) and sample rate ( ) settings.

method. Simply select the required cell number prior to scaling then scale using whichever

(or if external memory is used) at switch on. In addition

function). To scale any of these

and methods or

4.2 Display rounding

Display:
Range:
Default Value:

Displays and sets the display rounding value. This value may be set to 1 - 5000 displayed units.
Display rounding is useful for reducing the instrument resolution without loss of accuracy in applications where it is
undesirable to display to a fine tolerance. To set the display rounding value go to the

or push buttons to set the required value then press F to accept this selection.

Example:

function and use the

If set to

the display values will change in multiples of 10 only i.e. display moves from to to etc.

4.3 Memory chip address

Display:
Range:
Default Value:

This function is only seen when an external memory chip is connected. This function is used to display or set a unit
address to one or more optional external memory devices. For identification purposes each device should be
allocated a different address if more than one external memory is used. When a sensor with a memory chip is

plugged in the
from

address set. If a memory device has had an address set then the address can be viewed or altered at this function.
The procedure for setting or altering an address is as follows.

function can be used to view the address of the memory device. The address can be set

. If the default address is seen this indicates that the device has not had yet had an

1. The function must be set to either i.e. a memory device must be connected.

2. With the external memory device connected enter function mode and step through to the Unit function.

3. Use the

The address selected will now be stored in that memory device. The same address can be allocated to more than
one memory device and the address of a device can be changed at any time by following steps 1, 2 and 3 above.

or arrow to select the required address for that chip then press F to accept the change.

4.4 Decimal point place

Display:

Range:

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Default Value:

Displays and sets the decimal point place. By pressing the
be set. The display will indicate as follows:
decimal point places) or

(3 decimal point places).

(no decimal point), (1 decimal point place), (2

or pushbuttons the decimal point position may

4.5 Digital filter

Display:
Range:

Default Value:

Displays and sets the digital filter value. Digital filtering uses a weighted average method of determining the display
value and is used for reducing display value variation due to short term interference. The digital filter range is

selectable from
the filter level if required. Note that the higher the filter setting the longer the display may take to reach its final value
when the input is changed, similarly the relay operation and any output options will be slowed down when the filter

setting is increased. To set the digital filter value go to the

set the required value then press

to

to , where = none and = most filtering. Use or at the function to alter

function and use the or push buttons to

to accept this selection.

4.6 mV/V input range

Display:

Range:

Default Value:

Displays and sets the mV/V range to suit the transducer useable range. Choose the value equal to or the next
higher value to the mV/V output of the transducer. This selection sets the input range for the A/D converter. If too

low a range is selected a
the full resolution capability will not be used and problems with calibration can result.

error message will be seen on the display. If too high a range is selected

or

4.7 Sample rate

Display:

Range:
Default Value:

Sample rate for ADC - Displays and sets the ADC sample rate from 5 to 100 samples per second. The faster
sample rates can be utilized in features such as peak hold and peak/valley memory.

4.8 User pushbutton function

Display:
Range:

Default Value:

In normal measurement mode the User push button can be programmed to operate in one of the modes described
below. In CAL or FUNC modes pressing the User button will cause the instrument to immediately return to normal

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measurement mode. Any changes to the function selected when the button was pressed will not be saved. This
function may be set to any one of the following:

• - Button has no special function.

•

When tare is selected you can toggle between the nett, tare and gross displays via the User pushbutton. The
message

•
flash every few seconds. Press the F button to reset back to normal display. If the User button is held pressed
for 2-3 seconds the held value in memory will be reset and the current value will be held. The display will
automatically reset to normal measurement after 20 seconds. Holding the User button pressed in will cause the
held value to be reset and the value on the display after the reset will be held for as long as the button is
pressed down. The held display will only return to normal measurement 20 seconds after the button is released.

•

held pressed for 2-3 seconds the peak value in memory will be reset and a the current value will be become the
new peak value. The display will automatically return to normal measurement after 20 seconds. Alternatively if
the User button is held pressed down the peak reading will be held whilst the button is held pressed down and
will only return to normal measurement 20 seconds after the button is released.

•
(if memory chip is used) CH1,
(or

•

function. With the
User button is pressed the display value will be sent from the RS232 serial port in 8 bit ASCH format.

(Push button tare) - the pushbutton must be pressed for 2-3 seconds to perform a tare operation.

, or will precede the measurement value.

(Display hold) - Press the User button momentarily to hold the display, the message will

(Peak hold) - Press the User button momentarily to hold the peak value display the message
will flash every few seconds. Press the F button to reset back to normal display. If the User button is

(Change calibration channel) - Allows toggling between input readings for calibration channels

and . If switched off then the instrument automatically reverts to CH1

if memory chip is used) when switched on again.

(Output serial string to printer etc.) – The RS232 serial communications must be enabled to use this

function set to and the function set to each time the

4.9 First point for live input calibration

Display:
Range: Any display value
Default Value: n/a

Two point calibration scaling - this is an alternative calibration method to the
only one method needs to be used (See “Use of

). The and functions are used to set two independent calibration/scaling points of the
input to the display. This method uses two different live input values to scale the instrument. The method is as
follows:

and as reference values” if using and

method of scaling, note that

1. Enter the setup functions via mode and choose the required channel number at the function. The
channel number selected will be the channel for which this calibration scaling operation applies.

2. Step through the functions by pressing and releasing the F button until the display indicates

3. Press then release, the

4. The display will now indicate

5. Apply a known input to the instrument of nominally 0% (this value is not critical and may be anywhere within the
measuring range of the instrument). For example you could arrange that the load or pressure is zero at this time.
When the live reading has stabilized press the F button.

6. The display will indicate SCL1 (scale 1) followed by the scale value in memory.

7. Use the

8. Press the F button, the display will now indicate
complete).

or button to obtain the required scale value.

and buttons simultaneously to enter the calibration functions.

(1st calibration point) followed by a “live” reading.

(indicating that calibration of the first point is

.

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