Yokogawa µR20000 - Manual (Page 10)

1-3
SM 04P02B01-01E
Principles of Operation
1
Display / Panel Keys
• Offers a variety of display types, with a fluorescent character display tube (VFD) of
181 dots (horizontal) x 16 dots (vertical).
• Seven keys are available for operation and settings.
• White LEDs are installed for illuminating the z-fold chart paper. The LED can be
replaced.
Power Supply
A universal type power supply unit supplying a voltage of 100 V to 240 VAC at a
frequency of 50/60 Hz. The fuse is built in and cannot be replaced.
Instruments with the /P1 option support 24 VDC/AC (50/60 Hz), but cannot be used at
100 V to 240 VAC (50/60 Hz).
CPU
The following diagram shows the structure of the CPU Assembly.
DRAM ASIC
I/O interface
SRAM FLASH
memory
Battery Real time clock
CPU
• FLASH memory
The following are saved on the Flash ROM.
• Programs
• Ribbon shift adjustment data (dot model)
• Pen servo adjustment data (pen model)
• The mac address and related data
• System configuration data
• SRAM
The following are saved on the SRAM.
Data deleted in the RAM Clear process (backed up by battery)
• Zero/Span position
• Hysteresis adjustment data (dot model)
Data deleted in the RAM Clear process
• User settings (input range, etc.)
• Battery
A lithium battery. Backs up the SRAM and real time clock.
• ASIC
Contains interface functions for the motor and actuator, A/D converter, display, panel
key, and other items. Controls the pen servo mechanism.
• CPU and DRAM
Firmware is installed from flash memory to the DRAM. The CPU operates according
to the program in the DRAM.
1.1 Principles of Operation