Plc Md For The Operating System (System Bits) - Siemens SINUMERIK 840C Installation Instructions Manual

09.95
8.5

PLC MD for the operating system (system bits)

PLC MD
DB63
7
DW No.
6000 1)
DL 0
Default value: 0000 1111
This MD is used to enable the interchange of channel signals between NC and PLC. Because
the 840 system has a one-channel basic configuration, bit 0 must be "1". If there are several
channels, you must set the bits corresponding to the channels in this MD.
The highest channel number is specified for the PLC software in PLC MD 8. Options D32, D33
and D34 enable the use of as many as 4 channels (as from SW 4: 6 channels).
PLC MD
DB63
7
DW No.
6009
DR 4
Default value: All bits default to 0
M DECODING WITH EXTENDED ADDRESS FOR NC CHANNEL (1 TO 4)
Bit = 0 No M decoding with extended address
Bit = 1 M decoding with extended address
Note:
The relevant data block (DB 80 - DB 83) must be loaded to enable M decoding with extended
address. If the bit is set but the DB has not been loaded, the PLC goes into the STOP loop
(for a list of errors, see the Installation Lists).
After each restart, the PLC system obtains the information required from the relevant NC
machine data and stores it in the data blocks DB60 and DB63, which means that
- the other PLC MD remain active
- the PLC processes only those channels, spindles and axes actually defined via NC MD
- any changes in the number of channels, spindles or axes will become effective only after a
PLC restart.
_______
1) As from software version 3, these PLC MD are irrelevant, they are only used for display purposes
2) SW 4 and higher
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
Bit No.
6 5 4
2) 2)
6 5
Bit No.
6 5 4
2) 2)
6 5
6FC5197- AA50
8 PLC Machine Data (PLC MD)
8.5 PLC MD for the operating system (system bits)
3 2 1
Signals from/to NC channel
4 3 2
3 2 1
M decoding with ext. address channel
4 3 2
0
1
0
1
8–13