Outline
Section
1-1
19
1-1-7
Internal Mechanism of Loop Control Unit
The following describes the internal mechanism of the Loop Control Unit.
Function block data and error log data are backed up by internal battery in
RAM. During actual operation, the Loop Control Unit used the data in RAM.
Function block data is prepared and downloaded to RAM in the Loop
Control Unit from CX-Process Tool running on the computer.
From the CX-Process Tool, you can transfer data between RAM and flash
memory whenever necessary, or you can set the Loop Controller Unit to
automatically transfer the contents of flash memory to RAM whenever
power is turned ON. This enables operation without a backup battery.
(Error log data, however, is not backed up without a battery, i.e., it is not
store in flash memory.)
Error log data can be read using the READ ERROR LOG FINS command
(command code 2102 Hex). Error log data is not stored in flash memory.
In the default state, function block data is not stored on the Loop Control
Unit. Function block data must be downloaded from a computer before the
Loop Control Unit can be run.
Set whether or not to
transfer flash memory
contents to RAM at
startup.
I/O memory
Flash memory
RAM
Recover
Command
Download
The contents of RAM and flash
memory can be transferred back
and forth as requried.
DIP switch
Function block data
Back up
CPU Unit
Function block data prepared and
downloaded to RAM from CX-Process Tool
Loop Control Unit
Function block data sheet
(all function block data)
Stored error log data
Batter
Backup
Unit address
setting switch
(front panel)
At each operation execution
Every 1 second
Allocated data
Allocated
words
Note:
Function block data in RAM can be backed up to flash memory using the
CX-Process Tool. Refer to the CX-Process Tool Operation Manual for
details.
Function block data in flash memory can be restored to RAM. This can be
achieved either automatically at startup (set by turning ON pin 2 of the DIP
switch) or by using the CX-Process Tool. The use of the DIP switch is
described later in this manual. Refer to the CX-Process Tool Operation
Manual for details on using the CX-Process Tool.