Hitachi SJ Series, User Manual

Page: 511 / 786

14-20
Chapter 14 RS485 Communication
14.4.10 Storing a change made to retention
register
• The inverter doesn’t store the data of changes even
when the writing command to a retention register (06h)
and the writing command to multiple registers (10h) are
used.
• If the power of inverter is shut off without storying the
data, the data will be restored to the condition before the
retention register is changed.

ENTER instruction issuing method
• The writing of entire memory is performed when 1 is
written to a retention register (9000(DEC)) using the
writing command to a retention register (06h).
Cautions
• Do not turn OFF the power during data writing by an
ENTER instruction. If the power is turned OFF, the data is
not stored properly. Monitor the signal (coil No. 0049h)
during data wring to determine whether the data is being
written or not.
• Frequent use of ENTER instruction may shorten the life
of converter because the inverter’s memory element has
the limit of the number of rewriting times. Use of ENTER
instruction must be kept minimized, and especially
periodic and/or successive issuance of this instruction
must be completely avoided.
• To store in the inverter a change made to retention
register, you need to issue ENTER instruction in the
procedure shown below.
• To change control constants such as a motor constant,
you need to use ENTER instruction and recalculate
control processing internal variables.

Data writing mode
• The inverter enters the data writing mode when 1 is
written to a retention register (9002 (DEC)) using the
writing command to a retention register (06h).
• The data changed by the writing command to a retention
register (06h) after the inverter enters the data writing
mode will be written both in the RAM area for temporary
saving and in the ROM area for storying in the event of
power-off. Then simultaneously the data writing mode will
be released.
• If the inverter receives commands other than the writing
command to a retention register (06h) after entering the
data writing mode, the data writing mode will be released.
• Frequent use of data writing mode may shorten the life of
converter because the inverter’s memory element has
the limit of the number of rewriting times. Use of data
writing mode must be kept minimized, and especially
periodic and/or successive issuance of this mode must
be completely avoided.

Recalculation of control processing internal variables
• Recalculation of control processing internal variables is
performed when 1 is written to a retention register (9010
(DEC)) using the writing command to a retention register
(06h).
Parameter change
ENTER instruction
9000 (DEC)=1
Entire data is written
in a ROM.
Master
Inverter
Written in RAM.
Written in RAM.
Written in RAM.
Parameter change
Parameter change
ENTER instruction
Master
Inverter
EEPROM writing
mode enabled.
9002 (DEC)=1
Written in RAM and
ROM (only the data to
be changed).
Written in RAM.
Parameter change
Parameter change
Data writing mode
Data writing mode is enabled
only once for parameter
change.