@thodoris85 How do you get the sum of 257 when adding up the hex values. When I convert them to Dec. and do the addition I get a much different sum? OK I have also done this adding the hex values without converting to decimal and when I do that in your example it works, but when I do the same with the default values that were in my APIM it doesn't seem to come out right. is it possible the values were not correct from the start? Never mind I found my mistake, I was adding 07+00 not 07+D0 Sry to bother you and thanks for the hex lesson...