Siemens SIMATIC S7-300 Manual page 264

Writing Traversing Programs
Dwell G04 A traversing block with dwell can only contain M functions and the time pa-
rameter apart from this G function.
The following applies for dwell time:
Odd input values are rounded upward. Dwell times take effect only on a
block-by-block basis.
If no value is input for G04 in the block, the lower input limit applies.
Block change G60, With G60, the exact programmed position is approached and the feed move-
G64 (approach ment is stopped (exact stop block change).
conditions)
G64 causes the next block to be processed immediately as soon as the point
of deceleration is reached (change block on-the-fly).
G60 and G64 are mutually exclusive and self-maintaining.
M commands have no effect on G64 operation.
(For a detailed description, see Section 10.3).
External block
The "external block change" function causes a block change on–the–fly trig-
change (G50) with
gered by a digital input. The fast input must be parameterized with the "Ex-
delete residual
ternal block change" function by way of machine data item MD34.
path
The function takes effect only on a block-by-block basis (no effect on G60
and G64).
Example of exter-
The following figures show the program structure and program flow of an
nal block change
example of "External block change."
V
I
I
10-4
Lower input
Name
limit
Dwell time 2
/ N G1 G2 G3
10 50
20
N10
– digital input
Upper input
limit
100,000
X/t F M1 M2
10 000
N20
Í
Í
FM 354 Servo Drive Positioning Module
Unit
ms
M3 D
t
t