Frames Active In The Channel - Siemens SINUMERIK 840D sl Programming Manual

Channel-specific frames
$P_CHBFR[n]
System variable $P_CHBFR[n] can be used to read and write the basic frames. When a
basic frame is written, the chained total basic frame is not activated until the execution of a
G500, G54...G599 instruction. The variable is used primarily for storing write operations to
the basic frame on HMI or PLC. These frame variables are saved by the data backup.
First basic frame in the channel
The basic frame with field device 0 is not activated simultaneously when writing to the
predefined $P_UBFR variable, but rather activation only takes place on execution of a
G500, G54...G599 instruction. The variable can also be read and written in the program.
$P_UBFR
$P_UBFR is identical to $P_CHBFR[0]. One basic frame always exists in the channel by
default, so that the system variable is compatible with older versions. If there is no channel-
specific basic frame, an alarm is issued at read/write: "Frame: instruction not permissible".
5.7.2

Frames active in the channel

Function
Frames active in the channel are entered from the parts program via the associated system
variables of these frames. System frames also belong here. The current system frame can
be read and written via these system variables in the parts program.
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
Coordinate transformation (FRAMES)
5.7 NCU global frames
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