Siemens SINUMERIK 840D sl Programming Manual page 224

Flexible NC programming
1.25 Subprogram technique
Adjustable reload memory (FIFO buffer)
A reload memory is required in the NCK in order to run a program in "Execution from
external source" mode (main program or subprogram). The size of the reload memory is
preset to 30 Kbytes and, like all other memory-related machine data, can only be changed to
match requirements by the machine manufacturer.
One reload memory must be set for each program (main program or subprogram) to run
concurrently in "Execution from external source" mode.
Machine manufacturer
Please contact the machine manufacturer if the size and number of reload memories is to be
extended.
For further information about "Execution from external source", see:
References:
Function Manual, Basic Functions; Mode Group, Channel, Program Operation Mode (K1).
Block display, single block and behavior on NC stop
When executing from the hard disk and with EXTCALL, only the "Program run" HMI
Advanced 3-block display can be used. This setting applies for the single block or NC stop
status.
224
Note
Execution from external source via RS-232 interface with SINUMERIK powerline
In HMI Embedded, the "Execution from external source" softkey can be used to transfer
external programs across the RS-232 interface onto the NC.
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
Job Planning