
6. INTERPOLATION FUNCTION
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The G51.2 command is modal. Once specified, the P, Q, and R valuesstay
unchanged until another G51.2 is issued to change them or polygon
synchronized mode is released.
The S command issued to the first spindle during polygon synchroniza-
tion mode specifies that the second spindle be used as a polygon synchro-
nization axis and rotates at a speed of S
× Q/P with a phase difference
of R.
z G50.2
This command releases the polygon synchronization mode. This mode
is released also when:
(1) Reset
(That mode is not released by bit 0 (RPLM) of parameter No. 7603.)
(2)Power is turning off.
(3)An alarm condition occurs in the spindle control unit, and the serial
spindle control unit stops in an emergency on the PMC signals
*ESPA<G0071#1> and *ESPB<G0075#1>.
(4)P/S alarm 218, 219, or 221 occurs
G51.2 and G50.2 must be issued separately from other commands.
In a G51.2 issued to enter the polygon synchronization mode, R is
omissible, but P and Q are required.
After a G51.2 is issued to enter the polygon synchronization mode,
changing modal values of P, Q, and R requires another G51.2. In this case,
R can be specified separately from P and Q. However, P and Q must be
specified together even if only one of them is changed.
When a G51.2 is issued to start the spindle--spindle polygon synchroniza-
tion mode, the speed of the spindle (polygon synchronization axis) is
changed to Q/P times the speed of the first spindle (master axis) to achieve
a speed ratio of P:Q, and phase adjustment is performed.
(If no S command is issued to the first spindle after a G51.2, the previous
S command remains effective.)
If the spindle is in an acceleration, deceleration, or phase adjustment state,
synchronization at a rotation ratio of P:Q is not guaranteed. So, it is
necessary to control SAR<G0029#4> by checking the speed arrival
signal PSAR<F0063#2> for polygonal turning with two spindles or to
allow sufficient time in the program.
The method to specify the spindle speed during the polygon synchroniza-
tion mode is the same as for ordinary modes. However, each time an S
command is issued to the first spindle during polygon synchronization
mode, or a rotation ratio P:Q or phase value R command is re--specified
during the polygon synchronization mode, phase adjustment is performed
after speed control. In addition, speed commands (such as under multi-
spindle control or spindle output control for the second spindle by the
PMC) for the second spindle become ineffective.
If the specified polygon synchronization axis speed (S × Q/P for the
first spindle at S rpm) exceeds the clamp speed specified in parameter No.
7621, the polygon synchronization axis speed is clamped, and P/S alarm
No. 5018 is issued.
D Release command
D Cautions for using
commands
D Spindle operation during
the spindle--spindle
polygon synchronization
mode