Siemens SINUMERIK 840D sl, Function Manual

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Detailed description
2.8 Auxiliary functions without block change delay
Basic logic functions: Auxiliary Function Output to PLC (H2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
41
Programming examples
Programming examples of auxiliary functions with the corresponding values for output to the
PLC.
Programming syntax Output to PLC
DEF coolant = 12
- - -
DEF lubricant = 130
- - -
H[coolant]=lubricant
H12=130
H=coolant
H0=12
H5
H0=5
H=5.379
H0=5.379
H17=3.5
H17=3.5
H[coolant]=13.8
H12=13.8
H=‘HFF13’
H0=65299
H=‘B1110’
H0=14
H5.3=21
Error
2.8 Auxiliary functions without block change delay
Function
For auxiliary functions with parameterized and/or programmed output behavior, too:
•
"Output duration one OB40 cycle (quick acknowledgment)"
•
"Output prior to motion" or "Output during motion"
there may be drops in velocity in continuos-path mode (short traverse paths and high
velocities). This the system has to wait for acknowledgment of the auxiliary function by the
PLC toward the end of the block.
To avoid these velocity drops, the block change can be made irrespective of whether such
auxiliary functions have been acknowledged using machine data:
MD22100 $MC_AUXFU_QUICK_BLOCKCHANGE (block change delay with quick auxiliary
functions)
Constraints
Synchronism of auxiliary functions that are output without a block change delay is no longer
ensured for the part program block in which they are programmed. In the worst case
scenario, acknowledgment comes one OB40 cycle and execution of the auxiliary function
comes one OB1 cycle after the change to the next part program block.