IDEC SmartAXIS FT9Z-1A01, User Manual

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S
MART
AXIS P
RO
/ L
ITE
U
SER
'
S
M
ANUAL
FT9Y-B1378 5-9
5: S
PECIAL
F
UNCTIONS
Data Register ROM Backup
This section describes data register ROM backup.
Data Register ROM Backup Overview
Data register ROM backup is a function to write data register values to ROM (non-volatile memory), and then read the values in
ROM and store them in data registers at the desired timing. The SmartAXIS stores the device values using an internal backup
battery (lithium secondary battery). However, if the backup battery is dead due to a long term power loss, a memory backup error
will occur and the device values will be lost. In this situation, if you use data register ROM backup, you can initialize the data
registers with the values backed up in ROM. When a memory cartridge is installed, data is written to and read from the memory
cartridge.
*1
*1 When you use the Lite and a memory cartridge is not installed on the Lite, data register ROM backup cannot be used.
■ Applicable data registers
The applicable data registers are as follows.
■ ROM region
The ROM region that is used is as follows.
■ Special devices
Special internal relays
Special data registers
Note: When M8154 and M8155 are on in the scan end, writing and reading are executed in that order. After executing the read, the execution
status is stored in D8133, and M8154 and M8155 turn off.
Model number
12-I/O type 24-, 40-, 48-I/O types
Data registers D0000 to D0399 D0000 to D1999
Memory cartridge
Not installed Installed
Model
name
Pro
Pro Memory cartridge
Lite None (The data register ROM backup cannot be used.) Memory cartridge
Device Description
M8154
When M8154 is on at the end of scan, the values of all data registers are written to ROM. After all values are written,
the execution status is stored in D8133 and M8154 turns off.
M8155
When M8155 is on at the end of scan, the values in the corresponding ROM are read and stored to the data registers
specified by D8184 (starting address to read) and D8185 (number of registers to read). After all values are read, the
execution status is stored in D8133 and M8155 turns off.
Device Description
D8133
Stores the execution status for writing and reading.
1: Processing
2: Normal termination
3: Cannot access ROM
The following are possible causes:

The memory cartridge is not properly installed.

The ROM of Pro or the memory cartridge installed has failure.

On the Lite, reading or writing is executed when the memory cartridge is not installed.
4: Invalid values are stored in D8184 (starting address to read) and D8185 (number of registers to read)
This error occurs when reading values. The following are possible causes:

The number of registers to read is 0.

The start address to read exceeds the largest data register address.

The start address to read + the number of registers to read exceeds the largest data register address.
5: Valid data could not be read from ROM
This error occurs when reading. The following are possible causes:

No values are stored in the ROM.

Writing values did not finish for a reason such as the power was turned off while writing values.
D8184
Stores the start address of the data registers to read.
The value that can be specified is 0 to 399 for the 12-I/O type and 0 to 1999 for the 24-, 40-, 48-I/O types.
D8185
Stores the number of data registers to read.
The value that can be specified is 1 to 400 for the 12-I/O type and 1 to 2000 for the 24-, 40-, 48-I/O types.