Error in the console Error of register

[Carlos Padilla]

user-function-library 06.09.2017 11:09:30
Common functions:1: attempt to index global 'port' (a nil value)
stack traceback:
Common functions:1: in main chunk

does anyone know why I get this error when I execute the following command

a = { f1 = 10, f2 = 20 }





 for k,v in ipairs(a) do

 log(k,v)

 end



-- all passed arguments will appear in Logs module
log(a)