MKS SM 1280, Технические заметки

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page 12 of 27 File: SM1280_r7eng - April 2017 - Technical note: SM1280
SM 1280
This is the set-mode submenu: it
allows to select Manual or Exter-
nal Control.
In Manual mode the power can be
adjusted using the panel knob. In
External Control mode the manual
commands are not effective.
This is the set-efficiency
submenu: it allows to enter the
estimated value of magnetron
efficiency, range: 0-100% . If
you select 100% the “Microwave
Power” corresponds to the electri-
cal output power of the psu.
When the unit is in Alarm state
the cause is displayed until the
alarm is removed.
The CPU drives the unit to obtain an electrical output power
(Va * Ia) value proportional in a linear way to the reference
input signal. The scaling is 850W/V.
INTERLOCK FUNCTION: managed throu CONN# 4, pin 5 -
6, “MICROSWITCH ON COVER”. It is an external hardware
chain of contacts, that must be closed all at the time to have
the internal relay closed. (ON condition). When in ON the
CPU light-up the related Interlock OK led; in OFF state the led
is Off and the unit goes in Stand-by, as all dangerous voltages
on the head connector are off.
HEAD ENABLE 1, 2: CONN# 4, pin 7 - 9; CONN# 6, PIN
10 - 23 not implemented yet (version 1.0.1). Do not use, they
have no meaning.
Firmware upgrade
The software stored on the CPU (firmware, on a flash
memory) can be upgraded to a newer version using the RS232
serial port on the unit, connected to a PC.
Important remark: at power-on, even if a program is already
stored, the microprocessor enters a “BOOTLOADER” status,
lasting 2 seconds, during which it is possible to overwrite,
through the serial RS232 port, the stored code.
If no new code is loaded within 2 seconds, the previously stored
one is run.
To upload a new program through the bootloader, simply
connect the SM1280 serial port to the PC serial port, using a 9
pin 1:1 cable (only TX, RX and Ground are used, but also a full
cable will fit. See schematic on page 14)
No external switch must be operated, and the unit does not start
until the new program is stored, but be sure no enable signal is
active when upgrading.
The upgrade of the firmware embedded in the SM1280 is
released as a .zip archive named “ program_name.zip ”.
Unpacking the .zip archive you generate:
- a directory named “
program_name ” containing the micro
code to be loaded,
- an executable program named “
SendApplicationProgram.bat
”- and the loader “ sRecLoad.exe ”.
Once unpacked the .zip program
- enter in the folder “
program_name ”,
- switch-on the SM1280
- run
whithin 2 seconds the program “ SendApplicationProgra-
m.bat ” (which launches sRecLoad.exe application)
(This is the maximum time that the microprocessor bootloader
waits for new code to be loaded).
During the bootloader wait time, the red ALARM led is on: if
no code is sent, then the previous code is executed, and it is not
possible to change it without switching the unit off.
Meaning of external commands.
(vers 0 - 2 - 20 - 50)
HIBERNATE: has value ON/OFF. If ON the magnetron’s
filament is not powered and the SM1280 goes into Stand-by
mode.
In OFF the unit makes filament heating and, when the related
timer is elapsed, enters in Ready mode.
If a user don’t like to use the Hibernate function, he may not
connect the HIBERNATE control signal: the system then
detect it as in OFF condition.
POWER ENABLE: has value ON/OFF, but its effect is related
also with the Hibernate command as follow:
a) in OFF state - and HIBERNATE is OFF - the unit performs
filament preheating and goes in Ready mode but does not
generate output power, even if the reference signal is >0;
b) in OFF state - and HIBERNATE is ON - the unit is in
Stand-by mode but does not generate output power, even if the
reference signal is >0;
c) in ON state - and HIBERNATE is OFF - the unit waits the
end of preheating timer, if not yet elapsed, then starts to gene-
rate output power;
d) in ON state - and HIBERNATE is ON - the unit is in Stand-
by mode but does not generate output power, even if the
reference signal is >0.
POWER SET: it’s an analog input value and has the meaning
of “desired percent” of the full output power (8500W)
When this value is
lower than 1Vdc the unit does not gene-
rate any output power, when >1Vdc the unit generates power
proportional to this signal value.