System Variables Saved In Sram (Sw 6.3 And Later) - Siemens SINUMERIK 840Di sl Function Manual

Detailed description
2.3 Special real-time variables for synchronized actions
Figure 2-3
2.3.7

System variables saved in SRAM (SW 6.3 and later)

RESET response
The system variables $AC_MARKER and $AC_PARAM saved in SRAM retain their existing
values after RESET and Power On.
Note
In the case of part programs and synchronized actions that work with system variables
saved in SRAM, you must make sure that the variables are not initialized to 0 after RESET.
This may require some adaptation if system variables saved in DRAM have been used
previously.
36
FIFO variable
Function Manual, 11/2006, 6FC5397-5BP10-2BA0
Synchronized actions