Siemens SINUMERIK 828D Function Manual page 111

Remarks
System variables
The following system variables can be used in conjunction with synchronous actions:
● $AA_MEAACT (axial measuring active)
● $A_PROBE (probe state)
● $AA_MM1 ... 4 (probe position 1st to 4th trigger (MCS))
The following system variable cannot be used in conjunction with synchronized actions:
● $AC_MEA (probe has responded)
Measurement job
Only one measurement job at a time may be active for an axis.
Priority with more than one measurement
A new measurement task for the same axis has the effect that the trigger events are
reactivated and the measurement results reset.
Measurement jobs started from the part program cannot be influenced from synchronized
actions. If a measurement task is started from a synchronized action for an axis for which a
measurement task is already active from the part program, an alarm is displayed.
If a measurement task is already active from a synchronized action, measurement can no
longer be started from the part program.
Saving measurement results
A FIFO memory is set up in the $AC_FIFO system variables to save the measurement
results. See Section "FIFO variables ($AC_FIFO) (Page 30)".
Examples
In the following examples, two FIFO memories are set up via machine data:
● MD28050 $MC_MM_NUM_R_PARAM = 300
● MD28258 $MC_MM_NUM_AC_TIMER = 1
● MD28260 $MC_NUM_AC_FIFO = 1 (set up FIFO memory)
● MD28262 $MC_START_AC_FIFO = 100 (FIFO memory starts from R100)
● MD28264 $MC_LEN_AC_FIFO = 28 (22 variables + 6 management data)
● MD28266 $MC_MODE_AC_FIFO = 0 (no summation)
Synchronized actions
Function Manual, 07/2012, 6FC5397-5BP40-3BA0
Detailed description
2.7 Actions in synchronized actions
111