Brookfield DV-III Rheometer - Manual (Page 75)

Brookfield Engineering Laboratories, Inc. Page 75 Manual No. M/98-211-A0701
APPENDIX G - DV-III+ to Computer Command Set
The command set used to communicate with the DV-III+ is as follows:
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
Command Format from Host Response from Description
Rheometer
Where:
qqqq = Transducer reading as 4 hex digits. The instrument should yield a reading of approxi-
mately 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 2)
dddd = The ASCII characters "DV3+".
xx = The firmware version of the instrument (i.e. version 4.1 is returned as 41)
mm = These 2 characters will be used to represent the model for which the DV-III+ is
configured. The model decoding is shown in Table 1 below.