Siemens SINUMERIK 840Di Function Manual page 697

Note
The "Workpiece counter" function is independent of the tool management functions.
Activation
The workpiece counters are activated or the reset timing and counting algorithm are
specified via the following two channel-specific machine data:
MD27880 $MC_PART_COUNTER (activation of workpiece counters)
Bit Value Meaning
0 1 $AC_REQUIRED_PARTS is active
1 0 Alarm/VDI output with: $AC_REQUIRED_PARTS == $AC_ACTUAL_PARTS
1 Alarm/VDI output with: $AC_REQUIRED_PARTS == $AC_SPECIAL_PARTS
4 1 $AC_TOTAL_PARTS is active
5 1 With M2/M30: $AC_TOTAL_PARTS += 1
6 1 Equality under M function of $MC_PART_COUNTER_MCODE[ 0 ]: $AC_TOTAL_PARTS += 1
8 1 $AC_ACTUAL_PARTS is active
9 0 With M2/M30: $AC_ACTUAL_PARTS += 1
1 Equality under M function of $MC_PART_COUNTER_MCODE[ 1 ]: $AC_ACTUAL_PARTS += 1
12 1 $AC_SPECIAL_PARTS is active
13 0 With M2/M30: $AC_SPECIAL_PARTS += 1
1 Equality under M function of $MC_PART_COUNTER_MCODE[ 2 ]: $AC_SPECIAL_PARTS += 1
MD27882 $MC_PART_COUNTER_MCODE[ <Index> ] (workpiece counting via user-specific M function)
Index Meaning
0 Value of M function with which $AC_TOTAL_PARTS is counted up.
1 Value of M function with which $AC_ACTUAL_PARTS is counted up.
2 Value of M function with which $AC_SPECIAL_PARTS is counted up.
Boundary conditions
• All workpiece counters are set to the default values on control power-up and can be read
• If $AC_REQUIRED_PARTS = 0, no ID check is performed with the counter pulse for
Mode Group, Channel, Program Operation, Reset Response (K1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
and written independent of their activation.
$AC_ACTUAL_PARTS or $AC_SPECIAL_PARTS even if the MD bit is set.
Detailed Description
2.12 Program runtime/workpiece counter
2-161