What does the "41" that is prepended to the front of FP serial numbers?

[Ben]

I am developing an application that will use the FP controller's serail number as part of a license algorithm.

What does the "41" that is prepended signify?

When will this value be changing?

Any suggestions on how to plan for this value changing in the future without my knowledge and thereby shooting my code in the foot?

I realize I can just ignore these two characters but that will only work if this field will never be more than two characters.

So,

What does it mean and how should I handle it?

Ben

[Aaron_G]

Ben,

Currently, the upper byte of the 4 byte serial number is "41" for FP-1600 and FP-20xx controllers and "42" for FP-1601 controllers. This value may change in the future. I can not provide any information on when/how it may change. However, it is extremely unlikely that the serial number will change to be more than the 4 bytes (8 hex characters).

Regards,
Aaron