The PC monitoring program for the ultrasonic level neasure probe.
This program receives the Level Probe data's via the RS232
communication
port and shows all the probe parameters, and it also sends the commands
to the programmable Level Probe. A graphical drawing of the actual
representation
of the waves received by the ultrasonic transducer is shown on the
screen.
The patterns can be frozen with their own parameter setting. One can
then
proceed on another line, change any of the parameters and examine the
difference.
The program can record sequences of ultrasonic propagation shape
and
play them back by command button [#]. From this moment all data's
coming
from the probe will be recorded into a file. A sample file "Level.spl"
is also provided and can be played right after installation of the
Level
program.
The Level program is free to download.
Just click here to get the complete Level
program Setup (1 file).
The Level program gives all the information
concerning
the programmation of the probe with details on all the commands. For
experimenting,
the programmation of the parameters is easly made with the Level
program
where only mouse clicks are required but any (hyper) terminal program
where
characters can be typed in and sent can be used. View therefore the
list
of all commands that can be sent to the probe. A parameter can be
changed
by sending the corresponding command to the probe. The commands are
characters
code, sent/received via the built-in RS232 interface.
Command list. More details in the Level program.
Sending 1, 2 or 3 to the probe force
data's send
mode to; 1, send info non stop. 2, just before each new burst. 3, only
on request. This with the actual probe baud rate setting. The diagram
display
and the parameter refresh stop in mode 3. Request for a parameter value
is done with its appropriate command sent to the probe. [o] returns the
actual transmit mode.
? Returns the actual measured distance. ( ex: D2145 ) for
2145mm.
Check command receive mode, especially mode 3 where info's are only
send
on request with there apropriate command.
A Activates the Level Auto tune function. From there the
parameters
are adjusted in the probe in order to track the distance info over the
full range. If this parameter is saved into the probe, the Auto tune
mode
[A] is selected at power up.", 1, " [A] Auto tune. [a] returns
tune
mode.
B b Increases (*2) decreases (/2) the probe baud rate. This
new
value will only take effect if saved into the probe [W] and after
restart
[Z] or powerup. Choose maximum baud rate to speed up the graphic
diagram
refresh if used. Choose minimum baud rate for long distance
communication
between probe and PC or terminal where no graphic need to be displayed.
[x] returns the probe baud rate.
c Will return the probe temperature in 1/10 degrees
celcius.
The temperature is mesured under the circuit and next to the ultrasonic
transducer. This position give as result a close temperature value of
the
top air cullom in the pipe, but the bottom temperature of the bottom
remains
unknown.
D d Increases/decreases the dead time distance with 1cm.
Any
signal received in this time, short time just after the burst, will not
be marked as a valid distance echo. This distance should not be too
short
to prevent the burst noise to be taken as a valid echo signal. Sending
[m] to the probe return the Dead Time.
e Returns the Echo bounce. The echo bounce is the amount of
pulses
received by the transducer starting from the first one marking a valid
echo (after the Deadtime) until no more signal is received for this
last
burst. Increasing the burst length [R] and/or burst voltage [U], will
make
the sound wave produce more than one echo as visible on the line
diagram
and Eb. if too strong, the burst will make more dan one traject. Down
to
the liquid level, up and down and up again.
F f In/decreases the ultrasonic transducer frequency. This
25Kc,
very high quality transducer, still gives good result on other
frequencies.
The frequency is set by default to 25 Kilo-Cycles/s. But can be <
>
tuned. The new working Fq can be saved as the rest. If wanted, one can
replace the 25Kc transducer by a small band 40kc (maximum tested) type
without further change.
g Returns the Burst bounce (help if you know a better
name!).
The Burst bounce is the value of all received pulses just after the
burst
and before Dead time is elapsed. These are the oscillations of the
transducer
after the burst, the echo of the physic irregularyties of the mechanic
probe connection to the pipe, quasy immediate standing waves created by
the presure of the ultrasonic burst and the reflection of the air gap,
the channel that lets escape the air of the pipe. Notice value change
of
the Burst bounce while manually adjusting parameters.
Sending h to the probe makes it send back a small text
file containing
ALL available commands. This command is non relevant with the Level
program
where all this happens automatically, but helpfull when the ultrasonic
probe is used with a terminal or any simple communication program,
where
command characters are send manually one after each other.
I i In/decreases the interval between each ultrasonic
burst.
Choose a large interval if there is no need to have a high burst rate
when
only a distance level control (display or screen) is used and the
liquid
level is not supposed to change quickly. This may save power. As to the
life time of the transducer, it should not make any difference. The
transducer
is low voltage driven and passed long tests over 100V.
M Disables the Auto tune mode and sets the probe to manual
control.
Use Manual control to ajust any parameter. After power up or reset, if
Manual mode was saved, the probe starts to work with the saved
parameters
and will not adjust or change any. Manual mode enables to adjust the
working
of the probe on a selected range and pipe shape. [a] returns tune mode.
n Returns the (8bit) Pulse Wide Modulation value of the
transducer
output voltage driver. This is a control value using to tell if the
driver
is operating. On this low duty voltage, the driver is not likely to be
damaged. This feature is more useful for high tension probe.
R r In/decreases the periode amount sent with each
ultrasonic
pulse burst. The default setting is 4 periodes. Watch the burst noise
(Bd)
while increasing this parameter and make sure that the Dead Time is
long
enough. [P] returns the periode amount value.
S Resets all the parameters to default setting. The default
setting
can not be overwritten, but may be saved to the probe. Send default
command
[S] and read all default values with the Level program or after sending
[S] + [p] with a communication terminal.
W Writes (saves) all the (changed) parameters into the
probe
microcontroller non volatile flash EEPROM. By next power up or reset,
the
last saved parameters will be used for further processing.
T t In/decreases the temperature propagation coeficient of
ultrasonic
sound waves in air. This parameter is used by the micro-computer probe,
to calculate a more accurate time/distance echo. The default value is
0.60m/s/C.
This is approximately the general admitted increasing of ultrasound
propagation
speed in air per degree Celcius. Known as a Constant, there should be
no
need to change this value. But as all the other parameter it is
possible.
[k] Returns the coeficient.
U u In/decreases the burst voltage on the ultrasonic
transducer.
24dc probe supply will give a maximum of app. 20V on the transducer.
For
12Vdc, half of it. A few volt is enough with this high quality
transducer
for 3 meter in a clean PVC pipe. [s] return the burst voltage.
v V Decrease/increases the ultrasonic propagation speed
value.
The default value is 331,0 m/s. But because other factors can influence
the propagation speed of sound waves in air, the parameter can be
adjusted
to best knowledge. The parameter changes are made in steps of 0,1 m/s.
[w] Returns the us speed.
Z Resets the probe microcontroller. The probe will start
again
with the last saved parameters (W).
