Siemens Sinumerik 840D sl Programming Manual

Also see for SINUMERIK 828D Turning: Diagnostic manual Function manual Equipment manual Programming manual Operating manual

Motion synchronous actions10.3 Main run variables for synchronized actionsJob planningProgramming Manual, 02/2011, 6FC5398-2BP40-1BA0 57910.3.10 FIFO variables ($AC_FIFO1[n] ... $AC_FIFO10[n])Function10 FIFO variables (circulating buffer store) are available to store associated data sequences.Data type: REALApplication:• Cyclical measurement• Pass executionEach element can be accessed in read or writeFIFO variablesThe number of available FIFO variables is defined in machine dataMD28260 $MC_NUM_AC_FIFO.The number of values that can be written into a FIFO variable is defined using machine dataMD28264 $MC_LEN_AC_FIFO. All FIFO variables are equal in length.The sum of all FIFO elements is only generated if bit 0 is set inMD28266 $MC_MODE_AC_FIFO.Indices 0 to 5 have a special significance:Index Significance0 While writing: New value is saved in the FIFO.While reading: The oldest element is read and removed from the FIFO.1 Access to oldest stored element2 Access to latest stored element3 Sum of all FIFO elements4 Number of elements available in FIFO.Read and write access can be assigned to each element of the FIFO. FIFOvariables are reset by resetting the number of elements, e.g. for the first FIFOvariable: $AC_FIFO1[4]=05 Current write index relative to beginning of FIFO6 to nmax Access to nth FIFO element