Siemens SINUMERIK 840D sl Programming Manual page 650

Work preparation
3.8 Coordinate transformations (frames)
$P_TOOLFRAME
$P_WPFRAME
$P_TRAFRAME
$P_PFRAME
Current system frame
$P_CYCFRAME
P_ACTFRAME
FRAME chaining
$P_NCBFRAME [n] current global basic frames
System variable $P_NCBFRAME[n] can be used to read and write the current global basic
frame field elements. The resulting total basic frame is calculated by means of the write process
in the channel.
The modified frame is activated only in the channel in which the frame was programmed. If the
frame is to be modified for all channels of a control, $P_NCBFR[n] and $P_NCBFRAME[n] must
be written simultaneously. The other channels must then activate the frame, e.g. with G54.
Whenever a basic frame is written, the complete basic frame is calculated again.
$P_CHBFRAME[n] Current channel basic frames
System variable $P_CHBFRAME[n] can be used to read and write the current channel basic
frame field elements. The resulting complete basic frame is calculated by means of the write
process in the channel. Whenever a basic frame is written, the complete basic frame is
calculated again.
$P_BFRAME current 1st Basic frame in the channel
The predefined frame variable $P_BFRAME can be used to read and write the current basic
frame with the array index 0, which is valid in the channel, in the part program. The written basic
frame is immediately included in the calculation.
$P_BFRAME is identical to $P_CHBFRAME[0]. The system variable always has a valid default
value. If there is no channel-specific basic frame, an alarm is issued at read/write: "Frame:
statement not permissible".
$P_ACTBFRAME Complete basic frame
The $P_ACTFRAME variable determines the chained complete basic frame. The variable is
read-only.
$P_ACTFRAME corresponds to:
$P_NCBFRAME[0] : ... : $P_NCBFRAME[n] : $P_CHBFRAME[0] : ... : $P_CHBFRAME[n].
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TOROT and TOFRAME
Workpiece reference points
Transformations
Current programmable frame
For:
Cycles
Current total frame
Current frame is made up of the com‐
plete basic frame
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming