Siemens SINUMERIK 840Di sl Function Manual page 35

n=5: Current write index relative to beginning of FIFO
n= 6 to 6+nmax: Access to the nth FIFO-element:
Note
The FIFO access is a special form of R parameter access: (see below)
The FIFO-values are stored in the R-parameter range.
The FIFO values are stored in the static storage area. They are not deleted by end of
program, RESET or POWER ON.
The FIFO values are stored simultaneously when R parameters are archived.
Machine data
MD28262 $MC_START_AC_FIFO
defines the number of the R parameter, which marks the beginning of FIFO variables
storage in the R parameter area.
The actual number of R parameters in a channel is programmed in machine data
MD28050 $MC_MM_NUM_R_PARAM
is defined. The following two diagrams show a schematic representation of part lengths of
parts on a belt that have been stored in FIFO variables.
Figure 2-2
Synchronized actions
Function Manual, 11/2006, 6FC5397-5BP10-2BA0
Product lengths of sequence of parts on conveyor belt
2.3 Special real-time variables for synchronized actions
Detailed description
35