Siemens SIMATIC S7-300 Manual page 279

Influence of M Machine data can specify the output time for M functions:
function on block
change on-the-fly
M No.
1 – Output of M10 is not position-dependent, since no relevant position for
2 – At the block change from N5 to N10, output is prepared. The axis
3 – If two M functions are programmed in a traversing block, the first
4 – The change signal for M97 or M98 is output with the G64 block
FM 354 Servo Drive Positioning Module
M function is output before or after positioning with a block change
M-function output and positioning proceed in alternation.
– M function output before positioning causes exact-positioning re-
sponse in the preceding block.
– M function output after positioning causes exact-positioning response
within the block.
M function is output during positioning
M-function output and positioning proceed simultaneously.
The following figure shows a sample program with M function output
"during positioning".
/ N G1 G2 G3
5 90
10
15
20 60
V
N5 N10
1
2
3
10 000 20 000
10 20
a position-dependent M function is present.
the M function does not proceed until the actual position has reached the
programmed position of N5.
M function is output depending on position, followed by the second
M function.
transition (digital output) if the actual position has reached the
programmed position of the block. The actual position runs behind
the set position (difference = overtravel).
Writing Traversing Programs
X/t F M1 M2
10 000 100 00 10
20 000 20
30 000 200 00 30
40 000 150 00
N20
N15
4
30 000
30 40 97
M3 D
40
97
X
40 000
10-19