5.6.5 Restrictions on Internal Device Backup

Depending on the backup data capacity, screen display updates may become slower.
If the [Backup Start Address] + [Consecutive Addresses] exceeds the valid range of the internal device backup, the backup function will not work.
You cannot back up multiple user areas. If you select the LS area in the direct access method, only one of the two user areas (red frame portion in the diagram below) is backed up. This holds true for selecting the system area in the memory link method.
Data in backup memory (SRAM) is erased on:
Transfer Project (Send Project)
Offline mode's [Initialize User Memory]
Offline mode's [Initialize Backup SRAM]

Internal Device Backup Capacity

When backing up the internal device, backup memory (SRAM) usage is determined by the defined [Consecutive Addresses].

The capacity of the backup memory (SRAM) that you can use for backing up internal device data depends on the type of display unit and the space used by other data. For details about backup memory (SRAM), please see the following.
2.3 About the Display Unit's Internal Data
To check the backup memory (SRAM) usage, from the [Project (F)] menu, point to [Information (I)], select [Project Information (I)], and then select [SRAM Information].

Calculation

16+(4^*1 x Consecutive Addresses^*2)

*1 The value is 4 for the LS device address and the memory link. The value is 2 for the USR device address. If the [Consecutive Addresses] is an odd number, add 1 to the value.

*2 If you are using a model with a backup memory (SRAM) with a capacity of 128 KB, such as the GP4000 series, the [Consecutive Addresses] is doubled. If the [Consecutive Addresses] is an odd number, add +1 to the value and double it.

Calculation Examples

Backup Start Address: LS2096
Consecutive Addresses: 6096

[Calculation result]

(16) + (4×6096) = 24400 bytes (approximately 24 KB)