Data Storage In Feram Function - Mitsubishi Electric MELSEC-Q Series User Manual

3 SPECIFICATIONS

3.2.9 Data storage in FeRAM function

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POINT
(1) To disable the loop disconnection detection function, set 0 in Loop
disconnection detection judgment time (buffer memory address: 59, 91).
(2) If Loop disconnection detection dead band (buffer memory address: 60, 92) is
set, a loop disconnection is not detected even if there is no temperature
variation of 2 or more when the control output is provided 100% or 0% at the
set value (refer to Section 3.5.31).
(3) If a loop disconnection alert occurs frequently despite normal operation of a
sensor, load, and external operation device, check the following and take a
corrective action.
• Check if the capacity of a load (heater) and external operation device (cooling
fan) is enough.
If not, set a time value in Loop disconnection detection judgment time (buffer
memory address: 59, 91) longer than time required for varying 2
manipulated value 100%.
• Check that the set value is above the ambient temperature if the function is
used for heating control.
If not, set Loop disconnection detection dead band (buffer memory address:
60, 92) so that an alert will not occur near the ambient temperature.
(1) Storing data in FeRAM
(a) Data in the buffer memory of the Q62HLC can be stored in FeRAM for
backup. The backup target is the entire write-enable area excluding the
following areas.
For details of the buffer memory areas, refer to Section 3.5.
Buffer memory area name
Program control
PID constant read command from
FeRAM
Automatic backup setting after auto
tuning of PID constants
Hold command
Command advancing
Cascade ON/OFF
Forced output command
Forced output manipulated value (MV)
Write to FeRAM can be used to back up the PID constants set by auto
tuning and the data written directly to the buffer memory using a peripheral
device.
(b) The backed-up data is automatically transferred from FeRAM to the buffer
memory areas when the programmable controller CPU is powered on or
reset.
Using this function, users can execute PID control without writing data when
the programmable controller CPU is powered on or reset. A program for
setting data to the Q62HLC can be deleted.
MELSEC-Q
or 0.2% with
Buffer memory address (decimal)
57, 89
62, 94
63, 95
201, 217
202, 218
176
204, 220
205, 221
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