Siemens SINUMERIK 840D sl Function Manual page 278

K3: Compensations
5.4 Interpolatory compensation
● End position
The end position is the basic axis position at which the compensation table ends ⇒
interpolation point [k]. The compensation value of interpolation point [ k ] is used for all
positions larger than the end position; exception: Table with modulo function, see below.
$AN_CEC_MAX[<Index>] = <End position>
● Directional compensation
It is possible to set whether the compensation table should affect both traverse directions
equally or only the positive or negative traverse direction of the basic axis:
$AN_CEC_DIRECTION[<Index>] = <Direction>
– <direction> = 0: in both traversing directions
– <direction> = 1: in the positive traversing direction only
– <direction> = -1: in the negative traversing direction only
Application example:
Position-dependent backlash compensation by means of a compensation table per traverse
direction of the same axis.
● Table multiplication
For the table multiplication, the current compensation value is multiplied by the
corresponding compensation value of any other compensation table. The result is added
to the current compensation value and is output as the total compensation value.
$AN_CEC_MULT_BY_TABLE[<Index>] = <Table number>
– <table number > = 1, 2, 3, ... (2 * maximum number of axes), number of any desired
● Compensation with modulo function
When compensation with modulo function is activated, the compensation table is repeated
cyclically, i.e. the compensation value at position $AN_CEC_MAX[<index>] corresponding
to interpolation point $AN_CEC[<index>,<k>] is immediately followed by the compensation
value at position $AN_CEC_MIN[<index>] corresponding to interpolation point
$AN_CEC[<index>,0].
These two compensation values should be the same as otherwise the compensation value
jumps from MAX to MIN at the transition point and vice versa.
If modulo compensation is to be implemented with a modulo rotary axis as basic axis, the
compensation table used has to be modulo calculated as well.
$AN_CEC_IS_MODULO[<Index>] = <Value>
– <Value> = 0: Compensation without modulo function
– <Value> = 1: Compensation with modulo function
Example
MD30300 $MA_IS_ROT_AX[AX1]=1 ; rotary axis
MD30310 $MA_ROT_IS_MODULO[AX1]=1 ; modulo 360°
$AN_CEC_INPUT_AXIS[0] = AX1
$AN_CEC_MIN[0] = 0.0
$AN_CEC_MAX[0] = 360.0
$AN_CEC_STEP[0]=1.0
$AN_CEC_IS_MODULO[0] = 1
MD18342 $MN_MM_CEC_MAX_POINTS = 361
$AN_CEC[0, 0] = $AN_CEC[0, 360] = 0.1
278
compensation table or <table number> = <table index> + 1
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions