9. Miscellaneous Functions
9.1 Miscellaneous Functions (M8-digits BCD)
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9. Miscellaneous Functions
9.1 Miscellaneous Functions (M8-digits BCD)
Function and purpose
The miscellaneous (M) functions are also known as auxiliary functions, and they include such
numerically controlled machine functions as spindle forward and reverse rotation, operation stop
and coolant ON/OFF.
These functions are designated by an 8-digit number (0 to 99999999) following the address M with
this controller, and up to 4 groups can be commanded in a single block.
(Example)
G00 Xx Mm
1
Mm
2
Mm
3
Mm
4
;
When five or more commands are issued, only the last four will be valid.
The output signal is an 8-digit BCD code and start signal.
The four commands of M00, M01, M02, and M30 are used as auxiliary commands for
specific objectives and so they cannot be used as general auxiliary commands. This
therefore leaves 96 miscellaneous functions which are usable as such commands.
Reference should be made to the instructions issued by the machine manufacturer for
the actual correspondence between the functions and numerical values.
When the M00, M01, M02, and M30 functions are used, the next block is not read into
the pre-read buffer due to pre-read inhibiting.
If the M function is designated in the same block as a movement command, the
commands may be executed in either of the following two orders. Which of these
sequences actually applies depends on the machine specifications.
(1) The M function is executed after the movement command.
(2) The M function is executed at the same time as the movement command.
Processing and completion sequences are required in each case for all M commands.
The four M functions used for specific purposes will now be described.
Program stop : M00
When the tape reader has read this function, it stops reading the next block. As far as the NC
system's functions are concerned, only the tape reading is stopped. Whether such machine
functions as the spindle rotation and coolant supply are stopped or not differs according to the
machine in question.
Re-start is enabled by pressing the automatic start button on the machine operation board.
Whether resetting can be initiated by M00 depends on the machine specifications.