Convert CHAR to HEX in SAP system and functions

I tried to use the same function as mentioned; I am too getting the exception.

What I can make out of the dump thrown by the exception, only character type data objects are compatible with the function.

You can try using another function module ‘CRM_EI_KB_CONV_DEC_TO_HEX’  which is available in ECC 6.0 environment.

It will convert a decimal to hex and can be used. Hope it helps.