Miscellaneous Function M; H Function - Siemens SINUMERIK 808D ADVANCED Programming And Operating Manual

8.11

Miscellaneous function M

Functionality
The miscellaneous function M initiates switching operations, such as "Coolant ON/OFF" and other functions.
A small part of M functions have already been assigned a fixed functionality by the CNC manufacturer. The functions not yet
assigned fixed functions are reserved for free use of the machine manufacturer.
Note
An overview of the M miscellaneous functions used and reserved in the control system can be found in Section "List of
instructions (Page 258)".
Programming
M...
Effect
Activation in blocks with axis movements:
If the functions M0, M1, M2 are contained in a block with traversing movements of the axes, these M functions become
effective after the traversing movements.
The functions M3, M4 and M5 are output to the internal interface (PLC) before the traversing movements. The axis
movements only begin once the controlled spindle has ramped up for M3, M4. For M5, however, the spindle standstill is not
waited for. The axis movements already begin before the spindle stops (default setting).
The remaining M functions are output to the PLC with the traversing movements.
If you would like to program an M function directly before or after an axis movement, insert a separate block with this M
function.
Note
The M function interrupts the G64 continuous path mode and generates exact stop:
Programming example
N10 S1000
N20 X10 M3 G1 F100
N30 M78 M67 M10 M12 M37
M30
Note
In addition to the M and H functions, T, D and S functions can also be transferred to PLC (Programmable Logic Controller).
In all, a maximum of 10 such function outputs are possible in a block.
8.12

H function

Functionality
With H functions, floating point data (REAL data type - as with arithmetic parameters, see Section "Arithmetic parameter R
(Page 104)") can be transferred from the program to the PLC.
The meaning of the values for a given H function is defined by the machine manufacturer.
Programming
H0=... to H9999=...
Programming and Operating Manual (Milling)
6FC5398-4DP10-0BA1, 01/2014
;Max. 5 M functions per block
;M function in the block with axis movement, spindle
accelerates before the X axis movement
;Max. 5 M functions in the block
;Max. 3 H functions per block
103