Owner manual

Brookfield Engineering Laboratories, Inc. Page 76 Manual No. M/98-211-A0701
Model mm
LV LV
2.5LV 4L
5LV 5L
RV RV
RV 1R
RV 2R
HA HA
2HA 3A
2.5HA 4A
HB HB
2HB 3B
2.5HB 4B
5HB 5B
Table 1 - DV-III+ Model Decoding
Invalid cmd received 1 x x x x x x x
Diagnostics error x x 1 x x x x x
Motor circuit error x x x 1 x x x x
Auto-zero complete x x x x 1 x x x
Motor speed = 0 x x x x x 1 x x
Motor On (Energized) x x x x x x 1 x
Control circuitry enabled x x x x x x x 1
Table 2 - Status Byte <ss> Definition
Note: These values are not updated in the status byte when the listed condition occurs. They are
made available when the computer next sends a command that includes the status byte in the re-
sponse. The flags are cleared when the condition causing a flag to be set has been resolved or by re-
enabling (E command) the DV-III+.
The DV-III+ must first be issued the E(nable) command to enable control circuitry and ascertain its
current status. The DV-III+ will respond with an echo of the E(nable) command and will append the
current status <ss> of the DV-III+. This 2-digit status byte will provide information as to the
rheometer's internal working condition and capability to continue with or to accept new tasks.
The Z(ero) command is used to "zero" the DV-III+ rheometer. The value returned <zzzz> is usually
in the range of 03F0 hex to 0400 hex. This number should be retained and subtracted from every
future returned torque reading to obtain the actual rheometer torque in percent.
The rheometer torque value and current temperature may be obtained by issuing the R(etrieve)
command. The DV-III+'s response to this command is to echo the command: R(etrieve) and then
follow it with 8 hex digits comprising the current values for the rheometer torque <qqqq> and the
temperature probe reading <tttt>. Any control program written to exploit the output of the DV-III+
will have to perform all the calculations required for viscosity, shear stress and shear rate, etc. The
DV-III+ will be directed to run at a given speed through the use of the V(elocity) command. Unlike
the two previous commands, this command requires the parameter <vvvvv> which contains the value
for the desired speed. The DV-III+ responds to this command by repeating the command:
V(elocity) and appending the status byte <ss> which will, amongst other things, inform the calling
program as to whether the motor was turned on and/or whether the desired speed was attained.