Specifications

Positioning IP 240
Transferring modified distance values for the switching and signalling ranges
with control FB 168 in direct data interchange
You must first enter the new distance values
in the data block.
Initialize the FB as follows:
: JU FB 168
NAME : STEU.POS
:
FKT : 6,0
You must specify the following job numbers
to transfer the new distance values:
• For channel 1: 10
H
• For channel 2: 20
H
If the bytes with offset 0, 4 and 8 are also
transferred, they must first be set to ”0”.
10.18.3 Changing the Zero Offset
You can specify either a relative or an additive zero offset (NVER).
The actual value is modified as follows when a zero offset is transferred:
Relative zero offset
Actual
new
=Actual
old
+ Zero offset
rel., new
- Zero offset
rel., old
Additive zero offset
Actual
new
=Actual
old
+ Zero offset
add., new
You can transfer relative or additive zero offsets in any order. Note, however, that the next
relative zero offset to follow an additive zero offset is based on the value NVER
rel.,old
=0.
Example: Actual value=0
NVER = 1000 is specified as relative zero offset:
Actual value=1000
NVER = 500 is specified as additive zero offset:
Actual value=1500
NVER = 2000 is specified as relative zero offset:
Actual value=3500
NVER = 1500 is specified as relative zero offset:
Actual value=3000
Every time the actual value is synchronized, it is set to the value of the zero offset last transferred,
regardless of whether this was a relative or an additive zero offset.
In direct data interchange, the ADD bit is used to specify the type of zero offset:
ADD=0 for a relative zero offset
ADD=1 for an additive zero offset
10-68 EWA 4NEB 811 6120-02a