
B–64113EN–1/01
9. SPINDLE SPEED FUNCTION
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The spindle–speed function strobe signal SF <F007#2> and
spindle–speed function code signals S00 to S31 <F022 to F025> are
output to the PMC. (However, parameter setting is required to enable
output of the S codes and SF signal. See the description of each bit of
parameter No. 3705.)
At this time, the PMC must determine whether gear switching is to be
performed, and perform gear switching as required. The selected gear
must be reflected in the gear selection signals (input) GR2 and GR1
<G028#2, #1> for notification to the CNC.
From GR2 and GR1, the CNC determines which gear is selected.
However, note the difference between the M series and T series, as
described below.
M series: Up to three gear stages are supported. If the fourth gear stage
is selected, it is assumed that the third gear stage is selected.
T series: Up to four gear stages are supported for the first spindle, and
up to two gear stages for the second spindle. (The gear
selection for the second spindle/third spindle is notified to the
CNC by the signal GR21 <G029#0>.)
An S code is output in the first block (positioning to tapping position) of
G84 (G74) execution. However, the spindle motor position loop is closed
in the next block (R point positioning). Accordingly, spindle speed offset
must be adjusted accurately until the position loop has been closed in the
second block of G84 (G74) execution after the PMC activates the spindle
motor with M29. Otherwise, the spindle motor may rotate slightly. (This
applies only to an analog spindle. No offset adjustment is required for a
serial spindle.)
Rigid tapping mode may be specified by specifying M29 before G84,
specifying M29 and G84 in the same block, or by specifying G84 as a G
code for rigid tapping. In each case, PMC processing is the same. (The
M29 code is always output.)
D When T–type gear
selection is used