ALTER SM1150, Техническая заметка

Страница: 12 / 30

page 10 of 29
File: SM1150_r5eng - February 2007 - Technical note: SM1150
SM 1150
File: SM1150_r5eng - February 2007 - Technical note: SM 1150
page 11 of 29
SM 1150
Software specifications
At present the following versions of software have been distri-
buted:
-
ver. 1.04
(V104) see the menu config. at page 12
-
ver 2.01
(V201) to
ver 2.05
(V205) see the menu config. at
page 11.
Main Characteristics of ver. 1.04:
The version 1.04 has a complex menu organization, with all
the functions than can be reached and selected by means of the
front panel commands only. In addition the Ver. 1.xx allows to
choose between 5 different control modes of the output:
1- Open Loop control : the reference signal sets the anodic
current and the control loop is performed only by hardware,
the CPU does not execute any control. I.e.: 1V = 90 mA, 5V
= 450 mA, 10V = 900 mA. This mode is equal to the control
mode of any unit without CPU (like the SMx45, SM1050,
SM1180): if the anode voltage does not vary then the power
is costant. The precision of the control is driven only by
precision/tolerance of the hardware.
2- Current Loop control : the reference signal sets the anodic
current and the control loop is performed also by the CPU.
I.e: 1V = 90 mA, 5V = 450 mA, 10V = 900 mA. If the anode
voltage does not vary then the power is costant. The precision
of the control is improved by the CPU which reduces hardware
drift for temperature modification.
3- Forward Power control : the reference signal sets the r.f.
forward power and the feedback signal should come from a
power sensor installed on the load cavity or waveguide.
I.e: 1V = 300 Wrf, 5V = 1500 Wrf, 10V = 3000 Wrf. It is useful
only if the feedback signal from the power sensor is true and
quite stable.
4- Power control : the reference signal sets the electrical
output of the power supply unit: the CPU reads continuously
the anodic voltage and adjusts the anodic current to keep the
output power constant.
I.e: 1V = 500 Wdc, 5V = 2500 Wdc, 10V = 5000 Wdc. The
precision and repeatability of the output is within 1% of full
scale.
5- Table control : the reference signal sets the electrical power
needed by the magnetron to get a presetted r.f. power. It is
useful to linearize the r.f. power with reference to the signal.
The “Table” is a set of 20 values of electrical output power that
has the effect to produce the 20 corresponding r.f. power by the
magnetron: intermediate values are calculated by the CPU with
linear interpolation. The 20 r.f. values start from 300 (Wrf)
up to 3000 W, with steps of 150 W (300, 450, 600, 750....): at
each of these steps corresponds a DC power that the unit has to
produce.
The SM1150 has a “default” Table (20 prestored values) that
can be used at any time and is not erasable by the user: in addi-
tion the software allows to load customized values that may be
used instead of those of the default Table.
To customize the Table it’s required to have a power meter
connected to the microwave cavity and then to select a table
step, adjust the power with the panel knob till the power
meter’s reading is the same. See more details on the Menu
Descriptions.
Main Characteristics of ver. 2.01:
The version 2.01 has a simplified menu organization and
the default control mode is the Table mode. The other two
control modes available, Open Loop and Forward Power, can
be selected only by means of the remote control with a PC,
connected thru the serial port RS232, and the specific program
“FrontPanel” distributed togheter with the unit. See the rele-
vant paragraph “The FrontPanel program”.
For the basic explanation of the control modes see the previous
paragraph about characteristics of the ver 1.xx
With reference to the “Control Menu Configuration” at page 11
there are the further explanations of the symbols and names;
the numbers enclosed in bracket [ ] into description refer to
the small numbers associated to names or functions on the
drawing. The description apply to drawing of the version 1.04
too.
[1, 2, 3, 4, 5, 6]
WORKING MODE
:
see “Working Mode” para-
graph at page 8.
[7]
DISP
: entering this menu you select what value the unit
DISPLAYS
between the following [8] :
POW DC power (Watt)
%POW Percent of output power
FPOW Forward Power (Watt)
RPOW Reverse Power (Watt)
CURR Anodic Current (mA)
VOLT Anodic Voltage (Volt)
Once selected the measured value is displayed only when the
unit is in MW-ON state.