I have an Absolute encoder with Petherick code. It gives me 5 separate digits. Every digit have 4 bits with Petherick code system, so I have this situation:

xxxx xxxx xxxx xxxx xxxx - 5 separate groups with independent circular code advance:


encoder output / decimal value


0101 0
0001 1
0011 2
0010 3
0110 4
1110 5
1010 6
1011 7
1001 8
1101 9
1001 8
1011 7
1010 6
1110 5
0110 4
0010 3
0011 2
0001 1
.
.
.
.
.
.
.

0101 0
0001 1
0011 2
0010 3
0110 4
1110 5
1010 6
1011 7
1001 8
1101 9
1001 8
1011 7
1010 6
1110 5
0110 4
0010 3
0011 2
0001 1
.
.
.





As you can see, I have an circular sequence of 18 digits in clockwise turning.


On which way I can measure absolute position?