Siemens SINUMERIK 840Di Function Manual page 1416

Detailed Description
2.12 Block descriptions
General
Blocks FC 19 (M version), FC 24 (slim-line version), FC 25 (T version) and FC 26
(HPU/HT6 version) transfer the machine control panel to and from the application interface.
In the input parameters, "ModeGroupNo" selects the mode group to be processed by the
block. The "ModeGroupNo" parameter also selects the number of the machine control panel.
"ChanNo" selects the channel to be processed. The "SpindleIFNo" parameter defines the
axis interface of the spindle. The spindle override is transferred to this spindle interface. The
parameters are checked for errors. Output parameters "FeedHold" and "SpindleHold" are
generated from the 4 feed/spindle disable and feed/spindle enable keys and are returned
with "logical 1" for disable. Information for the next cycle is stored in DB8, bytes 0 to 3 or
bytes 62 to 65, depending on the machine control panel number. This information is the
edge trigger flag, feed value and selected axis number. The blocks are provided with user
data via the pointer parameters in DB 7 MCP1In and MCP1Out (MCP2In and MCP2Out).
The pointers are addressed indirectly via a further pointer from the VAR section of DB7 in
order to avoid absolute addressing. This additional pointer is determined symbolically in FB1.
Block Description
All four blocks have a similar structure. The blocks are organized into separate sections for
individual subtasks.
In the Input network, various parameters are copied to local variables. The machine control
signals (user data for input/output area) are also copied between locations using the various
pointers in DB 7 (gp_par). These local variables are handled in the block for reasons of
efficiency. Some values are initialized for the start-up.
MCS/WCS switchover with edge evaluation, axis selections, direction keys and rapid
traverse overlay is determined in the Global_in network for further processing in the block.
User-specific modifications should be made to this Section of the program. The user-specific
modifications will usually mainly involve axis selections.
Only the keyswitch information is copied in Network NC.
The mode group network transfers the modes of the keys as dynamic signals to the NCK.
The INC checkback signals from the NC are stored temporarily for the corresponding LEDs.
If the mode group number is 0, this network is not processed. If the number is too large,
message 401901 or 402501 is output and the control switches to Stop mode.
In the Channel network, the NC Start, Stop, Reset and Single Block functions are activated
by corresponding checkback signals. The direction keys of the geometry axes are supplied if
a corresponding preselection is made, otherwise they are cleared. If the channel number is
0, this network is not processed. If the number is too large, message 401902 or 402502 is
output and the control switches to Stop mode.
The Spindle network transfers the spindle override to the interface configured via
SpindleIFNo.
The Axes network transfers the feedrate override to the selected axis interface. The direction
keys are assigned to the selected axis/spindle. If an axis has been selected previously, the
direction information is set to 0.
The output parameters are prepared and the LED signals of the INC machine function are
generated in the Global_OUT network.
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PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0