09.95 6 NC Machine Data (NC MD), NC Setting Data (NC SD)
6.2 General machine data (general data)
Number of Execution Memory Sectors
30
Default value Lower input value Upper input value Units
10 5 1 000 Sector
Active on
Power On
Active: on POWER ON
When ”Working from external” or from the hard disk, the part program is read into a circular
buffer which executes the program at the same time. The circular buffer is part of the part
program memory. The size of the circular buffer is defined in NC MD 30 as number sectors
(1 sector = 507 bytes).
Active RS232C (V.24) or Sinec H1
External mass
storage
Unassigned circular buffer
Block pointer for execute
Full circular buffer
Block pointer for reading in
Circular
buffer
Program
execution
Sinumerik 840C
If the specified sectors are not available to the circular buffer on NC Start (either occupied by
part programs or part program memory too small), the circular buffer is reduced to the
maximum possible number of sectors by the control.
Additional machine data: (MD 130*, MD 5148-5152, option bit)
If processing is to take place from more than 1 interface, an appropriate area is reserved for
each of these interfaces.
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 6–15
SINUMERIK 840C (IA)