
B–63173EN–1/01
9. SPINDLE SPEED FUNCTION
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The S command specifies the spindle speed entered from machining
programs, etc. for the CNC.
For constant surface speed control (during G96 mode), the CNC converts
the specified surface speed to the spindle speed.
With bit 4 (GTT) of parameter No. 3706 = 0 without the constant surface
speed control option, the CNC specifies the gear stage for the desired
spindle speed to the PMC according to parameter No. 3741, 3742, and
3743, and the S command.
(GR3O, GR2O, GR1O <F034#2, #1, #0>)
With the spindle serial output or spindle analog output option, the spindle
control function in the CNC converts the S command value to the output
value for the spindle motor. For correspondence to gear change and
constant surface speed control, the S code/SF signals output is different
as follows in case of the spindle serial output and spindle analog output
are not used.
Outputs the S code.
The SF signal is output only when the CNC directs the PMC to change
the gear.
If you use the S code for processing in the PMC ladder, you must specify
parameters related to parameter No. 3705.
This signal sets the S command value in the CNC to 0. If the CNC has
the spindle output specified (see descriptions on the SIND signal), this
signal sets the speed command for the spindle to 0.
Even if the function of the spindle stop signal is not used, the signal must
be set to logical 1 for the CNC to perform spindle speed control.
If the spindle orientation signal is logical 1 and the spindle stop signal is
logical 0, the spindle rotates in the direction specified by bit 5 (ORM) of
parameter No. 3706 at a constant speed specified by parameter No. 3732.
Because the spindle rotates at a constant speed regardless of the gear
stage, this signal can be used to rotate the spindle to drive the stopper or
pin during mechanical spindle positioning.
Specifying bit 1 (GST) of parameter No. 3705 causes the spindle motor
to rotate at constant speed. This function can be used for gear shifting
because it maintains a constant speed of the gear change mechanism.
When spindle orientation is in progress, setting this signal to 1 keeps the
gear shift mechanism at a constant rotation speed, so the signal can be
used for gear shifting. This signal implements a function equivalent to
that of the GST parameter (bit 1 of parameter No. 3705). It is valid if GST
is 0.
This signal specifies an override of 0% to 254% for the specified S value
for spindle control.
However, the spindle speed override function is disabled when the CNC
is in the following state:
D S command
D S code/SF signal output
D Spindle stop signal
(*SSTP)
D Spindle orientation
signal (SOR)
D Gear shift signal (*GST)
D Spindle speed override
signal (SOV00 to SOV07)