File: SG524_r3eng - April 2017 - Technical note: SG 524 page 9 of 16
PM 250
SG 524
in EXTERNAL the power is controlled only by reference
signal 0-10V (to be supplied on the signal connector) and
in REMOTE the reference value is set through the fieldbus
module. Confirm the selection with Enter.
[8] PARAM Frequency: on this page you can set the ope-
rating frequency if the manual tuning is set. If automatic
tuning is set you will only be able to visualize the frequency
value. You can also see a moving bar which refers to the ratio
between Reverse/Forward power (R/F xx%).
[9] PARAM Frequency Tuning: moving the front panel knob,
you can choose between the Manual tuning mode and the
Automatic tuning mode.
The term “Tuning” in this context is used for the searching
for a working frequency, within the permissible band from
2400 MHz to 2500 MHz, exhibiting the lowest ratio between
Reverse and Forward Power figures (Rev/Forw or simply
indicated as R/F).
Selecting Manual Tuning you will have the possibility to
change the frequency from the previous menu PARAM Fre-
quency [8].
With Automatic Tuning the algorithm we have implemented
will find the best frequency out of the broad range of frequen
-
cies for that cavity.
As an example see the next drawing, where a hypothetical R/F
curve is plotted: the algorithm is able to find frequency point
“A” a where the lowest R/F ratio is. It will stay there even if
point “B” also represents an optimal frequency, but not the
lowest, regardless of the starting frequency, which could be
anywhere on the spectrum.
The unique given conditions to reach point “A” are
- ratio R/F greater than 10%
- ratio at point “B” smaller than 2% if compared to the maxi-
mum R/F ratio. If larger than 2% the algorithm may decide to
“converge” and stabilize the frequency around this point.
The first frequency from which the autotuning starts is the
last frequency, set manually and at which the generator was
running before entering into autotune mode.
The user may adjust the various parameters, via three buttons
and a rotating knob on the front panel, as follows:
-
ESC
button: used to return back to previous page without
saving
-
TAB
(arrow) button: moves to the next page
-
Enter
button: confirms the selection highlighted on the
display. When in MW ON status (see next description) pres-
sing the Enter button stops the emission of microwaves and
returns the unit to READY mode (performs the same function
as removing the Enabling command)
-
Adjust Knob
: rotate to move the selection within the
displayed page or change the par/-)
Following is the explanation of the various pages. The number
enclosed in brackets [ ] refers to the small number associated
to names of pages in the previous layout.
[0,1]: At POWER ON the unit shows the Logo, its name and
software version for a moment and then enters into READY
state [2]. You can exit from this page in two ways:
- adjusting the power reference with the front panel knob,
or external/remote command, and going to MW ON [3] state.
(What you see on this page depends on what you have set on
the DISPLAY [5] page);
- by pressing the ESC button you can go to DISPLAY page.
Here you can decide what you want to see (which parameters)
on MW ON page.
[2, 3, 4] These are the same READY, MW-ON, ALARM
modes as described in the previous chapter “Working Modes”.
[5] DISPLAY:
on this page you can decide which type of para-
meter is displayed in MW ON mode. Selectable parameters:
- the Reference signal (0-100%)
- the Internal Unit Temperature (°C detected inside the unit)
- the Forward Power (Wrf, detected at the output)
- the Reverse Power (Wrf, detected at the output)
- the Frequency (MHz, set on “PARAM Frequency” [8])
- the REV/FWD ratio
[6] INFO: this page shows the last alarm that occured, the sof-
tware version the generator is running, the total working hours
of the unit in MW ON and READY states.
[7] MODE: with the knob you may select to run the unit in
MANUAL or EXTERNAL or REMOTE. In Manual mode the
output power is adjusted using the rotating knob on the panel,
A
B
0
max
% R/F
10%
<2%
2.4 GHz
2.5 GHz
f
