Siemens SIMATIC FM 353 Manual page 288

Writing Traversing Programs
Set actual value on-the-fly G87, G88, G89
The "Set actual value on-the-fly" function is programmed and triggered by a digital
input; the block change occurs on the fly and the actual value is set to a new di-
mension (programmed coordinate) at the same time. The digital input must be
parameterized with the "Set actual value on-the-fly" function by way of machine
data item MD34.
Example of set actual value on-the-fly
The following figures show the program structure, program flow and actual-value
curve for an example of "Set actual value on-the-fly."
/ N
10
15
20
25
V
N10
I
N10
0 50 100 150 200 250 300 350 400
System of
measurement
shifted
I − digital input
10-6
G1 G2 G3 X/t
90 100
89 (88)
300
90
400
87
N15 N20
Reversal of direc-
tion
Í
I
N15
N20
50 100 150 200 250 300 350 400
0
F M1 M2
400 000
50 200 000
400 000
400 000
N25
N25
X System of measure-
ment normal
FM 353 Stepper Drive Positioning Module
M3 D
t
t
X
6ES7 353-1AH01-8BG0