Loading Plc Machine Data - Siemens SINUMERIK 880 SW 6 Planning Manual

1 General Overview

1.3.2 Loading PLC machine data

1.3.2 Loading PLC machine data
As far as the machine data are concerned, a distinction is made between MD words and MD
bits. The PLC machine data are also broken down according to target groups; PLC machine
data words and bits exist, for example, for the PLC operating system, function blocks and the
PLC user program.
The PLC machine data are stored together with the NC machine data in the machine data
submodule (COM area). Each PLC has its own machine data. The machine data can be
entered at the operator panel or read in via the universal interfaces.
When a PLC cold restart is performed, the PLC machine data are transferred to the relevant
data blocks of the PLC and thus made available to the user program.
COM
MD words
1)
MD 0
PLC operating system
(MD 200)
MD 2000
(MD 2250)
Function blocks
MD 4000
(MD 4100)
User
MD bits
1)
MD 6000
PLC operating system
(MD 6100)
MD 7000
(MD 7250)
Function blocks
MD 8000
(MD 8050)
User
Loading PLC machine data on cold restart
–––––––
1) The machine data contain the MDs for both PLCs; they are transferred to the relevant PLC when a cold
restart is performed.
1–20
Machine data words
DB 60
0 0
Operat-
ing
system
149
159
Cold restart
Machine data bits
DB 63
0 0
Operat-
ing
system
49 39
© Siemens AG 1991 All Rights Reserved
01.93
PLC I (PLC II)
DB 62
DB 61
0
Function User
blocks
49
DB 64 DB 65
0
Function User
blocks
24
6ZB5 410-0HE02
SINUMERIK 880 (PJ)