Lenze Global Drive PLC Developer Studio - Manual (Page 84)

8.3 Memories
Drive PLC
Appendix
8−4
L
DrivePLC DE 6.0
8.3 Memories
The below table gives you an overview of the memories available:
Memory Size Info
ROM
Program memory 256 kbytes Re−written whenever the program is downloaded.
RAM
PLC data memory 10 kbyte Can be symbolically used for FB instances and PLC variables.
24 kbytes
(as of version 7.x)
Application data memory 2 blocks
à 64 kbytes
Data get lost after mains disconnection.
E2PROM−buffered memory
Retain memory 200 bytes See subsection 8.3.1
Tip!
Function library LenzeMemDrv.lib includes functions for read/write access to the additional backup
memory (application data memory) of the PLC.
·
Additional information can be found in the Manual for function library LenzeMemDrv.lib.
8.3.1 Retain memory
In the retain memory the values of the retain variables are stored safe from power failure and are thus
available to the program even after mains switching. (Saving with C0003 = 1 is not required.)
·
Retain variables are declared by means of the variable class
VAR RETAIN.
·
Retain variables are created as a symbolically addressable memory.
·
With each program download the retain variables are reset to their initialisation value. If an
initialisation value has not been defined, the corresponding retain variable will be initialised
with the value "0".
·
In the DDS online mode you can use the commands Online
W Reset (cold) and Online W
Reset (original) to reset the retain variables in the PLC to their initialisation values.
8.3.2 Downloading data
In DDS (as of version 2.0) it is possible to attach a file to your project whose data is automatically
downloaded to the PLC when the program is downloaded.
·
This mechanism is, for instance, used in the Software Package − Cam to download motion
profiles.
Note!
·
With the 9300 Servo PLC the additional data is loaded into the application FLASH.
·
With the Drive PLC the additional data is directly attached to the PLC program because the
Drive PLC does not have an application FLASH.