PROGRAMMING
B–63684EN/01
12. AUXILIARY FUNCTION
121
In general, only one M code can be specified in a block. However, up to
three M codes can be specified at once in a block by setting bit 7 (M3B)
of parameter No. 3404 to 1. Up to three M codes specified in a block are
simultaneously output to the machine. This means that compared with
the conventional method of a single M command in a single block, a
shorter cycle time can be realized in machining.
CNC allows up to three M codes to be specified in one block. However,
some M codes cannot be specified at the same time due to mechanical
operation restrictions. For example, M42 can be specified only after the
mechanical operation of M41 is completed. For detailed information
about the mechanical operation restrictions on simultaneous specification
of multiple M codes in one block, refer to the manual of each machine tool
builder.
M00, M01, M02, M30, M98, M99, or M198 must not be specified
together with another M code.
Some M codes other than M00, M01, M02, M30, M98, M99, and
M198 cannot be specified together with other M codes; each of those M
codes must be specified in a single block.
Such M codes include these which direct the CNC to perform internal
operations in addition to sending the M codes themselves to the machine.
To be specified, such M codes are M codes for calling program numbers
9001 to 9009 and M codes for disabling advance reading (buffering) of
subsequent blocks. Meanwhile, multiple of M codes that direct the CNC
only to send the M codes themselves (without performing internal
operations ) can be specified in a single block.
One M command
in a single block
Multiple M commands
in a single block
M40 ;
M50 ;
M60 ;
G00G91X0Y0 ;
:
:
:
M40M50M60 ;
G00G91X0Y0 ;
:
:
:
:
:
12.3
MULTIPLE M
COMMANDS IN A
SINGLE BLOCK
Explanations
Examples