Siemens sinumerik 840d Programming Manual page 358

Motion-Synchronous Action
10
10.3 Special real-time variables for synchronized actions
840 D
NCU 572
NCU 573
Programming example
Circulating memory
During a production run, a conveyor belt is used to
transport products of different lengths (a, b, c, d).
The conveyor belt of transport length "I" therefore
carries a varying number of products depending on
the lengths of individual products involved in the
process. With a constant speed of transport, the
function for removing the products from the belt
must be adapted to the variable arrival times of the
products.
DEF REAL INTV=2.5
DEF REAL TOTAL=270
EVERY $A_IN[1]==1 DO $AC_FIFO1[4]=0
EVERY $A_IN[2]==1 DO $AC_TIMER[0]=0
EVERY $A_IN[2]==0 DO $AC_FIFO1[0]=$AC_TIMER[0]*$AA_VACTM[B]
EVERY $AC_FIFO1[3]+$AC_FIFO1[4]*BETW>=TOTAL DO POS[Y]=-30
$R1=$AC_FIFO1[0]
10-358
810 D 840Di
CCU2
;If the light barrier is free, calculate and store in the FIFO the product length from
the time measured and the velocity of transport.
;As soon as the sum of all product lengths and intervals between products is greater than
or equal to the length between the placement and the removal position, remove
the product from the conveyor belt at the removal position, read out the product
length out of the FIFO.
Constant distance between products placed
on the belt.
Distance between length measurement and
removal position.
Reset FIFO at beginning of process.
If a product interrupts the light barrier, start
timing.
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) – 04.00 Edition
12.97
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