Specifications
IP 240 Position Decoding
Transfer of the initial values from the data block to the IP 240
The limit values are initially transferred to the IP with configuring FB 169.
During operation, you can enter modified limit values with control FB 170.
• Transfer by calling configuring FB 169
Enter the limit values which are to be transferred to the IP in DR 29. In DR 29, one bit is
assigned to each track. ( Table 7.4)
• Transfer by calling control FB 170
Enter the track whose limit values are to be modified in DR 29. Choose only those tracks
whose limit values were transferred with configuring FB 169.
Now call control FB 170 and parameterize function 4 ”Write initial and final track values”.
Table 7-4. Identification of the Tracks to be Transferred
7 6
DL 29
DR 29
Data
word
5 4 3 2 1 0
0
TR6
0
TR5
0
TR4
0
TR3
0
TR2
0
TR1
Bits
0
TR8
0
TR7
TRn =1 the track limits for this track are to be transferred to the IP
=0 the track limits for this track are not to be transferred to the IP
Example: You have set bits 2, 4, 5 and 7 in DR 29 on configuration. Limit values for tracks 3, 5, 6
and 8 are transferred to the IP.
1. You now wish to modify the limit values for track 5. Set only bit 4 of DR 29.
Now call control FB 170.
2. You wish to use track 7 and transfer the limit values to the IP. You set bit 6
and call control FB 170. In DW 13 you will find error code KH=0207 ”Limit
values for track 7 cannot be transferred”.
Monitoring the reference tracks
The actual value is compared with the track limits ANFn and ENDn in every module firmware
cycle. If the actual value is within a track (including limits), the status bit (REF 1 to REF 8) assigned
to the track is set.
If the initial value exceeds the final value, the corresponding REFn bit is not set for any actual
value.
Should a signal decoding error or range violation occur ( Section 7.2.6), the status of the REFn
bits is frozen. The REFn bits are not updated again until the comparison of the actual value with
the track limits is reinitiated
• following a new reference point approach ( Section 7.2.9) or
• following transfer of a zero offset.
EWA 4NEB 811 6120-02a
7-5