High-speed RAM operation function
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5.18 High-speed RAM operation function
When using the high-speed RAM operation function, some restrictions apply to the program operation and
data saving. Thoroughly understand the specifications before using this function.
(1) Overview
The robot programs are saved in the RAM (SRAM), which is backed up by the battery.
These programs can be executed with SRAM operation or DRAM operation. Select the operation method
with parameter: ROMDRV. The default setting is DRAM operation (high-speed RAM operation). DRAM
operation can execute at a faster speed (maximum 1.2 times faster than SRAM operation), but some restric-
tions apply to the saving of variables used in the program when shutting the power off.
Restrictions
SRAM operation: All variables are saved.
DRAM operation: The program’s external variables are saved. The local variables and user-defined
external variables are discarded.
Select the robot program operation (DRAM operation or SRAM operation) according to the application.
Change the parameter: ROMDRV shown in
, and then turn the power off and on. Refer to
83, "3.15 Operation of parameter screen"
for details on changing the parameters.
Table 5-14:List of ROM/high-speed RAM operation parameters
Table 5-15:Role of each memory and relation of ROMDRV parameters
Parameter
Description and value
ROMDRV
Switches the program execution (operation) between SRAM operation and DRAM operation.
0= SRAM operation
2= DRAM operation (default value)
Memory
type
Feature
ROMDRV
parameter
0 (SRAM mode)
2 (DRAM mode)
SRAM
Data not lost at power off
Data lost when batteries are
spent
Read/write enabled
Execution of programs
(Discard the execution result)
Program control operation
Note1)
System data read/write
Note2)
Common variable read/write
Program read/write
Note1) Program control operation refers to operations such as copying, deleting or renaming the program in the
controller using the T/B or personal computer support software.
Note2) System data saving includes “parameter save”, “error log save”, and the data files read and written by the
program (OPEN/PRINT/INPUT).
Program control operation
System data read/write
Common variable read/write
Program read/write
DRAM
High-speed execution
possible
Data lost at power off
Program execution
(execution results discarded)
