Mitsubishi Electric MELSEC-Q Series User Manual page 52

3 SPECIFICATIONS
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(2) Writing data to FeRAM
(a) To write data to FeRAM, turn on FeRAM backup start command (Yn8).
• FeRAM write completion flag (Xn8) turns on at completion of data write to
FeRAM. After FeRAM backup start command (Yn8) is turned on, it takes
more than 10 seconds until FeRAM write completion flag (Xn8) turns on.
• FeRAM write failure flag (XnA) turns on if the write processing is not
completed successfully.
(b) Make changes to buffer memory when FeRAM write completion flag (Xn8)
is off.
Programmable
controller CPU
1) Yn8 : ON
(Write command)
3) Xn8 : ON
(completed)
(3) Reading data from FeRAM
Data is read from FeRAM under the following conditions.
• When the programmable controller CPU is powered on or reset.
• When PID constant read command from FeRAM (buffer memory address: 62,
94) turns on. Note that the read data are only the PID constants and loop
disconnection detection judgment time of the corresponding channel.
Q62HLC
OS
2) Write
Buffer
memory
data
Read
At power-on
or reset
MELSEC-Q
FeRAM
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