
B–63503EN–1/01
11. PROGRAM COMMAND
587
By specifying indexing positions (angles) for the indexing axis (one
rotation axis, A, B, or C), the index table of the machining center can be
indexed.
Before and after indexing, the index table is automatically unclamped or
clamped .
The control axis that indexes the index table can be named A, B or C. It
will be referred to as “B” in the following discussion.
The positioning angle for the index table is commanded by the numerics
following “B” in the program command, which is an independent block.
Both absolute and incremental commands are possible, but the value after
“B” is the integer times the numeric set by the parameter:
(Example) G00G90B100000; Absolute command
(Positioning angle 10 degrees)
G00G91B20.0; Incremental command
(Move distance 20 degrees)
There are two variations of the procedure (type A and type B) to set the
index table position; the difference is in the ON/OFF timing of the
position control servo. The sequence of events and the difference between
the variations are described below, followed by time charts showing them
graphically.
(1)Assume Bbbbb is ordered by the command program.
(2)The CNC turns the B axis unclamp signal BUCLP <F061#0> to “1”.
(Type B -- When BUCLP is turned to “ 1 ”, the position control servo
for the B axis is turned ON.)
(3)On the PMC side, the clamp of the B axis is released; when completed,
the B axis unclamp completion signal *BEUCL <G038#6> turns to
“0”.
(4)The CNC then turns the B axis unclamp signal BUCLP to “0”, to
indicate it received the *BEUCL signal.
(5)When the PMC is notified that BUCLP has been turned to “0”, the
PMC should turn *BEUCL to “1”.
In type B, B–axis unclamp signal BUCLP is turned to “0”, B–axis
position control is made in servo–on state, B–axis is rotated, and the
B axis is stopped at the specified position. B axis always moves at
rapid traverse.
(6)When the B axis stops at the specified position, CNC turns B–axis
clamp signal BCLP<F061#1>to 1. In type A, signal BCLP is set to “1”
and B–axis position control is made in servo–off state.
(7)When BCLP is turned to “1” on the PMC side, the B axis is clamped
mechanically (with a clutch or shot pin, for example). When the clamp
is completed, the B axis clamp completion signal *BECLP <G038#7>
is turned to “0”.
11.9
INDEX TABLE
INDEXING FUNCTION
(M SERIES)
General
Basic Procedure