M Functions - Siemens Sinumerik 840D sl Programming Manual

Auxiliary function outputs

14.1 M functions

Function outputs in continuous-path mode
Function outputs before the traversing movements interrupt the continuous-path mode (G64/
G641) and generate an exact stop for the previous block.
Function outputs after the traversing movements interrupt the continuous-path mode (G64/
G641) and generate an exact stop for the current block.
Important: A wait for an outstanding acknowledgment signal from the PLC can also interrupt
the continuous-path mode, e.g. for M command sequences in blocks with extremely short
path lengths.
14.1 M functions
The M functions initiate switching operations, such as "Coolant ON/OFF" and other functions
on the machine.
Syntax
M<value>
M[<address extension>] = <value>
Meaning
M:
<address extension>:
<value>:
Predefined M functions
Certain important M functions for program execution are supplied as standard with the control:
M function
M0*
M1*
M2*
M3
M4
M5
M6
344
CAUTION
Meaning
Programmed stop
Optional stop
End of program, main program (as M30)
Spindle clockwise
Spindle counter-clockwise
Spindle stop
Tool change (default setting)
Address for the programming of the M functions.
The extended address notation applies for some M functions (e.g.
specification of the spindle number for spindle functions).
Assignment is made to a certain machine function through the value
assignment (M function number).
Type: INT
Range of values: 0 ... 2147483647 (max. INT value)
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
Fundamentals