8 CPU Unit Functions
8-14
NJ-series CPU Unit Software User’s Manual (W501)
When the end of the life of the SD Memory Card is detected, save the data on the SD Memory Card
and replace the SD Memory Card.
The following system-defined variables show the status of the SD Memory Card.
*1 Precaution When Using SD Memory Card Access Flag (_Card1Access)
The SD Memory Card Access Flag is intended for use in notifying external devices. The status of access to the
SD Memory Card is not updated in realtime. Because of this, do not use the flag in the user program. Because
the status of access to the SD Memory Card is not shown in realtime, it may cause unexpected Controller
operation if you use it in the user program.
*2 Precautions When Using the SD Memory Card Power Interruption Flag ( _Card1PowerFail)
If the SD Memory Card Power Interruption Flag is TRUE, check to see if the correct file is in the SD Memory
Card and to see if the SD Memory Card operates properly. If the correct file is missing or the SD Memory Card
does not operate properly, download the correct file to the SD Memory Card again. Cycle the power supply to
the Controller or reset the Controller, and then see if the SD Memory Card operates properly. When you are
finished, change SD Memory Card Power Interruption Flag to FALSE. (_Card1PowerFail does not change to
FALSE automatically.)
Note Refer to 9-2 SD Memory Card Backups for the system-defined variables that are used with the SD Memory
Card backup function.
8-3-8 List of System-defined Variables Related to SD Memory Cards
Variable name Meaning Description
Data
type
_Card1Ready SD Memory
Card Ready
Flag
TRUE when the SD Memory Card is recognized. It is FALSE when
an SD Memory Card is not recognized.
TRUE: The Card can be used.
FALSE: The Card cannot be used.
BOOL
_Card1Protect SD Memory
Card Write
Protected
Flag
TRUE when the SD Memory Card is write-protected.
TRUE: Write protected.
FALSE: Not write protected.
BOOL
_Card1Err SD Memory
Card Error
Flag
TRUE when an unusable SD Memory Card is inserted or a format
error occurs.
TRUE: There is an error
FALSE: There is no error
BOOL
_Card1Access SD Memory
Card Access
Flag
*1
TRUE during SD Memory Card access.
TRUE: Card is being accessed.
FALSE: Card is not being accessed.
BOOL
_Card1Deterior
ated
SD Memory
Card Life
Warning Flag
TRUE when the end of the life of the SD Memory Card is detected.
TRUE: The end of the life of the Card is detected.
FALSE: The end of the life of the Card was not detected.
BOOL
_Card1PowerF
ail
SD Memory
Card Power
Interruption
Flag
*2
TRUE when the power supply to the Controller was interrupted dur-
ing access to the SD Memory Card.
TRUE: Power was interrupted during SD Memory Card access.
FALSE: Operation is normal.
BOOL
To Next Page
Loading...
Need help?
General
