Table of Contents
Advertisement
IP 240
b) Additive zero offset
The new actual value is computed as follows when you specify an additive zero offset:
The actual value thus changes by the value of the additive zero offset transferred.
Limit switch
Traverse
-10 000
range
NVER=0
1)
Traverse
- 10 000
range
NVER=1000
2)
Traverse
- 9 000
range
NVER=500
3)
Traverse
- 8 500
range
NVER=0
4)
Traverse
- 8 500
range
Explanation:
The values NVER=0, NVER=1000, NVER=500 and NVER=0 were transferred in
succession as additive zero offset.
Specifying the zero offset
When you structure the channel, the zero offset (NVER) is transferred to the IP 240 in data words
46 to 47. You can change the zero offset after configuring.
Note the following when specifying the zero offset:
•
If the channel is configured for a linear axis, NVER may be in the range from - 9,999,999 to
+ 9,999,999
•
If the channel is configured for a rotary axis, NVER must lie between +/- [final value for the
rotary axis].
In addition to the value for NVER, you must also specify the type of zero offset in D45/0 of the
data block (ADD bit).
ADD=0 for a relative zero offset
ADD=1 for an additive zero offset
EWA 4NEB 811 6120-02a
Actual
=Actual
+ Zero offset
new
old
Reference point
0
1 000
1 500
1 500
Fig. 10-20. Additive Zero Offset
add.,new
Limit switch
Current
+10 000
position
3 000
+10 000
4 000
+11 000
4 500
+11 500
4 500
+11 500
Positioning
10-27
Advertisement
Table of Contents
