problem reading R parameters of FM357-2 using "GET FB"

I am trying to read some R parameters of a FM-357-2 module using the GET function block(FB2),

I can read the parameters but the results are not ok.For RP0 to RP9 I can read the correct value but by incrementing each decade a fixed '6' offset is added to the R parameter address that FB2 returns, for example when I want to read RP11 I get the value stored in the R17 (11+6) or when I want to read R22 I get the value stored in R34 (22+6+6) and for R 34 I get the value stored in RP50 (34+6+6+6).

can somebody guide me what is wrong please.

Thaks in advance,