Siemens SINUMERIK 828D Function Manual page 1064

P3: Basic PLC Program for SINUMERIK 840D sl
13.13 Block descriptions
The input signal is evaluated in FC 26 with the help of the edge trigger flag. The active coordinate system is
shown in the following output signal:
• AB n + 0, Bit 0 (MCS/WCKS) with 0 = MCS, 1 = WCS
In case of active MCS the traversing key signals of the axes 1 - 6 are transferred in the axis-specific interfaces
(DB31, ... .DBX4.6 and DBX4.7 (traversing key +/-)) of the axes specified in the machine axis tables (DB10.DBB8
to DBB13 or DBB32 to DBB37).
In case of active WCS it is assumed that the axes 1 - 3 of the machine axis table are geometric axes. For this
reason the traversing key signals:
• of the axes 1 - 3 (EB n + 2 / 3, Bit 0 - Bit 2) are transferred in the interface of the geometric axes in
DB21, ... .DBB 12 + (n * 4), with n = 0, 1, 2), Bit 6 and Bit 7 (traversing keys +/-) of the channel specified with
the parameter "ChanNo" .
The assignment of the traversing key signals of the axes 1, 2 and 3 to the geometric axes 1, 2 and 3 of the
channel is permanent and may not be changed.
• of the axes 4 - 6 (EB n + 2 / 3, Bit 3 - Bit 5) are transferred in the axis-specific interface (DB31, ... .DBX4.6 and
DBX4.7 (traversing keys +/-)) of the axes 4 - 6 entered in the machine axis table (DB10.DBB11 to DBB13 or
DBB35 to DBB37).
No traversing of machine axes in WCS
In case of active WCS (AB n + 0, Bit 0 = 1) the traversing of the machine axes can be locked. For this, the
following output signals are to be set in the PLC user program:
• AB n + 3, Bit 7 = 1 (For WCS: no machine axes)
Requirement to the FC 26, not to transfer any traversing key signals for the machine axes. The traversing key
signals for the axes 1 - 3 of the machine axis table are transferred to the geometric axes 1 - 3 of the specified
channel. The traversing key signals for the axes 4 - 6 of the machine axis table are not transferred.
• AB n + 2, Bit 6 (axes 7 - n selected)
Requirement at the FC 26 not to transfer any traversing key signals, since the axes 1 - 6 of the machine axis
table are switched over. The axes 1 - 3 are thus not geometric axes, but instead also machine axes.
Feed override
The value of the HT8 override switch is transferred as feed override in the chanel-specific interface
DB 21, ... .DBB4 (feedrate override) of the programmed channel (parameter: "ChanNo") and in the axis-specific
interfaces DB31, ... .DBB0 (feedrate override) of the axes programmed in the table DB10.DBB8 to DBB13
(machine axis number).
Rapid traverse override
Is for the programmed channel (parameter: "ChanNo") the signal DB21, ... .DBX25.3 = 1 (feedrate override for
rapid traverse) set, the value of the HT8 override switch is set as rapid traverse override in this channel-specific.
Interface in DB 21, ... .DBB5 (rapid traverse override) and in addition the signal DB21, ... .DBX6.6 = 1 (rapid
traverse override active) is set.
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Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions