02.93
10 Data fields
10.2.2 PLC machine data words (DB 61)
Machine data for the definition of the two user bits for loading and unloading via
computer link
The computer link has four bytes in the loading and unloading message frames where either
32 bits or 4 ASCII characters are stored. This depends on the machine data bit MD 7001.7
(please refer to description of package 5). Via these four ASCII characters, four bits consisting
of two permanently assigned identification bits can be assigned on the one hand, namely:
•
DB 152 bit 0
: Tool life/number of pieces reached and
•
DB 152 bit 10 : Tool disabled
and, on the other hand, two user bits. The user bits are defined via the PLC machine data
MD 2078 and MD 2079.
The four signals are deleted when loading ASCII code 0 and set when loading ASCII code 1.
Correspondingly, ASCII codes 0 and 1 are output with respect to the states of the four bits
during unloading.
The target or source for the specification of the ASCII code are data words DW 32 and DW 33
of the correspondingly assigned dynamic buffer. The following assignments are valid:
•
DR 32 : DB 152 bit 10 (tool disabled)
•
DL 32 : DB 152 bit 0
(tool life/number of workpieces reached)
•
DR 33 : User bit 1
•
DL 33 : User bit 2
DW 78, DL
m+ 78
User bit 1:
Bit No.
Bit numbering from 0 to 15
MD No.
Description
DW 78,DR
m+ 78
User bit 1:
Data block number
MD No.
Description
DW 79, DL
m+ 79
User bit 2:
Bit No.
Bit numbering from 0 to 15
MD No.
Description
DW 79,DR
m+ 79
User bit 2:
Data block number
MD No.
Description
The bit numbers and the existence of the data blocks are not checked.
© Siemens AG 1991 All Rights Reserved 6FC5 197-0AA40-1BP1
10–19
SINUMERIK 840/880 (PJ)
