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Brookfield DV-III Ultra Rheometer User Manual

Page 125

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Brookfield Engineering Laboratories, Inc.

Page 125

Manual No. M/98-211-B0104

Brookfield Engineering Laboratories, Inc.

Page 125

Manual No. M98-211-E0912

The command set used to communicate with the DV-III Ultra is as follows:

Table I-1

COMMAND

FORMAT FROM HOST

RESPONSE FROM

RHEOMETER

DESCRIPTION

E(nable)

<E>

<E>

Enable control circuitry

R(etrieve)

<R>

<R>

Retrieve data

V(elocity)

<V>

<V>

Send speed

I(dentify)

<I>

<I> Identify instrument

Z(ero)

<Z>

<Z>

Zero instrument

Illegal String

<????>

<ss>

Invalid command

Where:

qqqq =

Transducer reading as 4 hex digits. The instrument should yield a reading of approximately

0400H after zeroing at rest. Calculate % torque as follows:

% Torque = tval/100

Where

tval is the decimal equivalent of the received torque packet.

zzzz

=

Transducer reading representing the % torque zero offset as 4 hex digits. Calculate the

decimal equivalent of the zero offset as follows:

Zero offset = tval/100

Where

tval is the decimal equivalent of the received zero offset packet. This value should

now be subtracted from all future % torque readings retrieved using the R command.

tttt

=

Temperature reading as 4 hex digits. Calculate temperature in °C as follows:

Temperature (°C) = (tval - 4000)/40

Where

tval is the decimal equivalent of the received temperature packet.

vvvvv =

Stepper motor speed as 5 hex digits. The motor speed command from the Host is in

units of RPM. To create a speed packet, multiply the desired decimal speed by 100 then

convert the result to hexadecimal. All packets must be 5 characters long so for packets

with less than that, pad the left side with zeros.

Example: To run the rheometer at 10 rpm

10 rpm x 100 = 1000 decimal = 3E8 hexadecimal;

padding with zeros results in 003E8 so the command sent would be V003E8

ss

=

Status Byte as 2 hex digits. (See Table I-3)

dddd =

The ASCII characters "DV3+".