Siemens SINUMERIK 840D sl Function Manual page 603

The four onboard outputs on the NCU and a total of 32 optional external NCK outputs are
available as the digital outputs of the NCK I/Os (see Section "A4: Digital and analog NC I/O
for SINUMERIK 840D sl (Page 29)").
Hardware assignment
The assignment to the hardware bytes used is made for each eight cam pairs in the following
general machine data:
● MD10470 SW_CAM_ASSIGN_FASTOUT_1
● MD10471 SW_CAM_ASSIGN_FASTOUT_2
● MD10472 SW_CAM_ASSIGN_FASTOUT_3
● MD10473 SW_CAM_ASSIGN_FASTOUT_4
Note
It is possible to define one HW byte for the output of eight minus cam signals and one HW
byte for the output of eight plus cam signals in each machine data.
In addition, the output of the cam signals can be inverted with the two machine data.
If the 2nd byte is not specified (= "0"), then the 8 cams are output as a logic operation of the
minus and plus cam signals via the 1st HW byte using the 1st inversion screen form.
Status query in the part program
The status of the HW outputs can be read in the part program with main run variable
$A_OUT[n] (n = no. of output bit).
Switching accuracy
Signals are output to the NCK I/Os or onboard outputs in the position control cycle.
As a result of the time scale of the position control cycle, the switching accuracy of the cam
signals is limited as a function of the velocity.
The following applies:
Delta pos = V
with:
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
* position control cycle
act
Delta pos = switching accuracy (depending on position control cycle)
V = Current axis velocity
act
N3: Software cams, position switching cycles - only 840D sl
Hardware assignment for output of cams
1 - 8 to NCK I/Os
Hardware assignment for output of cams
9 - 16 to NCK I/Os
Hardware assignment for output of cams
17 - 24 to NCK I/Os
Hardware assignment for output of cams
25 - 32 to NCK I/Os
9.3 Output of cam signals
603