Timer-Controlled Cam Signal Output - Siemens SINUMERIK 840D sl Function Manual

N3: Software cams, position switching cycles - only 840D sl
9.3 Output of cam signals
Example:
V
act
V
act
9.3.4

Timer-controlled cam signal output

Timer-controlled output
A significantly higher degree of accuracy can be achieved by outputting the cam signals
independently of the position control cycle using a timer interrupt.
The following machine data can be used to select the timer-controlled output to the 4 NCU
onboard outputs for 4 cam pairs:
MD10480 SW_CAM_TIMER_FASTOUT_MASK (screen form for the output of cam signals via
timer interrupts on the NCU)
In this case, the minus and plus signals of a cam pair are logically combined for output as one
signal.
Signal generation
Previously, it had to be specified in which way the signals to be logically combined should be
generated. This is realized using bit 1 in machine data:
MD10485 SW_CAM_MODE (behavior of the software cams)
Bit
1
Note
This function operates independently of the HW assignment selected in MD10470 ... MD10473.
The onboard byte may not be used a multiple number of times.
Restrictions
The following applies to the mutual position of the cam positions:
Only one timer-controlled output takes place per interpolation cycle.
If signal changes for more than one cam pair are active in the same interpolation cycle, the
output is prioritized:
The cam pair with the lowest number (1...32) determines the output time for all active signals,
i.e. the signal change of the other cam pairs takes place at the same time.
604
= 20 m/min, PC cycle = 4 ms
= 2000 rpm, PC cycle = 2 ms
Value Signal generation
0 Inversion of the signal behavior of the plus cam when:
plus cam - minus cam ≥ 180 degrees
1 No inversion of the signal behavior of the plus cam when:
plus cam - minus cam ≥ 180 degrees
Delta pos = 1.33 mm
Delta pos = 24 degrees
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions