Siemens SINUMERIK 840D sl Function Manual page 34

Detailed description
3.3 System variables for synchronized actions
Machine data
Number of FIFO variables per channel
The number of FIFO variables per channel is set using:
MD28260 $MC_NUM_AC_FIFO = <number of FIFO variables per channel>
Beginning of the R parameter range of FIFO variables
The R parameter, from which the range of FIFO variables for the channel begins, is set using:
MD28262 $MC_START_AC_FIFO = <number of the start R parameter>
Note
Free R parameters
Only the R parameters whose numbers are below the start R parameter of the FIFO variables,
can be written to the NC program.
Number of field elements for each FIFO variable
The maximum number of field elements per FIFO variable is set using:
MD28264 $MC_LEN_AC_FIFO = <number of field elements per FIFO variable>
Total number of R parameters in the channel
The total number of R parameters, which are required in the channel, is set using:
MD28050 $MC_MM_NUM_R_PAR‐
AM =
Summation of all user data
The sum of the values of all user data is only provided via $AC_FIFO[ 3 ] if the function is
activated via machine data:
MD28266 $MC_MODE_AC_FIFO, bit 0 = <value>
Value
FALSE The sum of the values of all user data is not provided
TRUE
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Meaning
The sum of the values of all user data is provided
MD28262 $MC_START_AC_FIFO +
MD28260 $MC_NUM_AC_FIFO *
(MD28264 $MC_LEN_AC_FIFO + 6)
Function Manual, 08/2018, 6FC5397-5BP40-6BA2
Synchronized actions