Retentive Data; Non-Retentive Data; Plc Machine Data; Plc Key Data - Siemens SINUMERIK 840D sl Function Manual

P4: PLC for SINUMERIK 828D
14.1 Overview
14.1.2.3

Retentive data

For the retentive data there are the user data blocks DB9000 - DB9063 and the data area
DB1400.DBW0 - DBW127. There the user can store all data that should remain valid after
POWER OFF/ON. The retentive data is stored in the non-volatile memory, however, not for
data backup.
14.1.2.4

Non-retentive data

Non-retentive data (e.g. bit memories, timers and counters) are deleted every time the control
is booted.
14.1.2.5

PLC machine data

The PLC machine data are in the NCK machine data area. At POWER ON, this data is
transferred by the PLC firmware into DB4500 of the PLC user interface where it can be
evaluated by the PLC user program.
References
SINUMERIK 828D Parameter Manual
14.1.3

PLC key data

The integrated PLC has a program memory of 24000 PLC operations which are completely
executed in one fixed PLC cycle.
A maximum of 500 operations can be executed in the INT0 interrupt program that can be
optionally used. It is executed servo-synchronous and allows the fastest possible reaction to
process events. This is the reason that interrupt-capable PLC I/O modules are not required.
Data
Main program (MAIN)
Subprograms (SBRx)
Interrupts
Time controlled interrupt
Alarms/messages
Bit memory
Counters
Timers,
of which:
User data block each with a max. of
512 bytes
Data transmission NCK ↔ PLC
1082
10 ms increment interval
100 ms increment interval
Number Special features
1
256
2
1 Servo-synchronous interrupt program
248 A maximum of 8 alarms is displayed.
4096 Non-retentive
64 Non-retentive
128 Non-retentive.
112
16
64 Address range DB9000 to DB9063
Via fixed parameterizable interface.
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions