Siemens SINUMERIK 840Di sl Function Manual page 117

Note
If the user does not wish to program any synchronized actions, then he can reset the value
to 0 in the machine data:
MD28250 $MC_MM_NUM_SYNC_ELEMENTS
In this way, around 16 kByte of DRAM memory can be saved.
Display
The status display for synchronized actions (see Section 2.9 "Diagnostics only with HMI
Advanced") indicates how much of the memory provided for synchronized actions is still
available. This status can also be read from synchronized actions in variable
$AC_SYNA_MEM.
Alarm
An alarm is generated if all available elements are used up during program execution. The
user can respond by increasing the number of synchronized action elements or by modifying
his program accordingly.
Number of FCTDEF functions
The number of programmable FCTDEF functions for each block can be configured via the
following machine data:
MD28252 $MC_MM_NUM_FCTDEF_ELEMENTS (number of FCTDEF elements)
The default value for all types of control is 3. The control-specific maximum value can be
found in:
References:
/LIS1/ Lists (Book 1); "MD/SD Lists".
Interpolation cycle
The time required on the interpolation level increases with the number of synchronized
actions programmed. It may be necessary for the start-up engineer to lengthen the
interpolation cycle accordingly.
Synchronized actions
Function Manual, 11/2006, 6FC5397-5BP10-2BA0
Detailed description
2.8 Configuration
117