01.93
6 NC Channel/PLC Interface (DB 10 ... DB 25)
6.6.1 General
You can declare the auxiliary functions and block information to rapid
d)
or slow with respect to
their output to the PLC.
After a slow auxiliary function or block information has been entered in the NC PLC program
and the change signal has been set, the control waits for an acknowledgement before initiating
a block change. The change signal remains set for one PLC cycle.
With rapid output to the PLC the control does not wait for acknowledgement from the PLC
program but initates the change immediately. The PLC program resets the change signal
immediately after transfer of the auxiliary function or the block information.
The auxiliary functions S and T and the block information D and F are declared to be rapid if
the appropriate bit in MD 542* is 1.
Declarations of the auxiliary functions H and M are non-modal. A minus sign in front of the
value makes the function rapid.
Example:
M = 03
slow auxiliary function
M = -03
rapid auxiliary function
Notes:
•
If a block contains several auxiliary functions, the rapid output to PLC is only activated
when all the auxiliary functions of a block are declared as rapid. The same goes for block
information.
•
If rapid output to PLC is used, it is not possible to stop part program execution in the same
block with the signal READ-IN DISABLE (DB 10...DB 25, DW 7...DW 10).
The following can still be determined via machine data:
•
Output of information before or at the beginning of the NC axis movement (NC MD 5003,
bit 2)
•
Which information is output with block search (NC MD 544*)
•
Output to PLC I, PLC II
•
Binary or BCD information output (NC MD 546*)
_______
d)
with GA2, software version 1 and higher
©
Siemens AG 1991 All Rights Reserved 6ZB5 410-0HE02
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SINUMERIK 880 (PJ)